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2025-04-08  Jim Meyering  <meyering@meta.com>

	version 3.12
	* NEWS: Record release date.

	tests: cmp: increase timeout to avoid failure on a very busy-IO system
	* tests/cmp: Increase timeout from 0.1 to 0.4s, to avoid false-failure
	on a system with lots of IO congestion. Reported by Nelson Beebe
	in https://lists.gnu.org/r/diffutils-devel/2025-04/msg00007.html

2025-04-04  Jim Meyering  <meyering@meta.com>

	build: update gnulib to latest; and update bootstrap

2025-03-28  Jim Meyering  <meyering@meta.com>

	maint: ensure that new "make syntax-check"-run sc_codespell passes
	* cfg.mk (codespell_ignore_words_list): Ignore false-positive "words".

2025-03-27  Jim Meyering  <meyering@meta.com>

	maint: rather than exempt "hight" as a spelling false-positive...
	* src/diff3.c (output_diff3): Rename lowt,hight to low_t,high_t.

2025-02-28  Paul Eggert  <eggert@cs.ucla.edu>

	tests: test for diff -y crash
	* tests/side-by-side-seq: New test.
	* tests/Makefile.am (TESTS): Add it.

	diff: fix allocation typo leading to crashes
	But reported by Nick Smallbone, with one-line fix by
	Collin Funk <https://bugs.gnu.org/76613>.
	* src/io.c (find_and_hash_each_line): Fix size computation.

	tests: make seq replacement more available
	This refactoring should let other future tests use ‘seq’.
	* tests/diff3 (seq): Move from here ...
	* tests/init.cfg: ... to here.

2025-02-21  Paul Eggert  <eggert@cs.ucla.edu>

	maint: mention bug#76452 in NEWS

2025-02-21  Collin Funk  <collin.funk1@gmail.com>

	diff: add a test case for the recent empty file bug
	* tests/empty-file: New file.
	* tests/Makefile.am (TESTS): Add the test.

2025-02-21  Paul Eggert  <eggert@cs.ucla.edu>

	diff: don't treat empty files as a different file type
	Reported by Kate Deplaix <kit-ty-kate@outlook.com> in
	<https://lists.gnu.org/r/bug-diffutils/2025-02/msg00005.html>.

	* src/diff.c (compare_prepped_files): Don't rely on string
	file type, as that might not agree with our idea of a file type.

2025-02-03  Simon Josefsson  <simon@josefsson.org>

	cmp, diff, diff3, sdiff: support gnulib-l10n
	* src/cmp.c (main): Call bindtextdomain for gnulib-l10n.
	* src/diff.c (main): Likewise.
	* src/diff3.c (main): Likewise.
	* src/sdiff.c (main): Likewise.

2025-02-02  Jim Meyering  <meyering@meta.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.11
	* NEWS: Record release date.

	maint: continue writing base64-encoded checksums to announcement
	* cfg.mk (announce_gen_args): Set to --cksum-checksums.

	tests: avoid "make check" hang on CentOS Stream 9 with valgrind-3.19.0
	* tests/init.cfg (require_timeout_): New function, from grep.
	(require_valgrind_): Use it, to kill -9 after 3 seconds, because the
	default SIGINT was insufficient.

	tests: avoid test failure due to inadequate Solaris 10 tr
	* tests/init.cfg (require_utf8_locale_): Solaris 10's /usr/bin/tr
	silently malfunctions with multibyte input, so attempt to find a
	better one, trying /usr/xpg4/bin/tr and "gtr".
	Failing that, skip the test.  Reported by Collin Funk in
	https://lists.gnu.org/r/diffutils-devel/2025-02/msg00004.html

	maint: once again distribute .tar.gz files
	* configure.ac: Reenable distribution of gzip-compressed tarballs,
	to help reduce the size of the Guix seed, as discussed at
	https://lists.gnu.org/r/coreutils/2020-02/msg00042.html and
	https://lists.gnu.org/r/sed-devel/2020-01/msg00013.html
	* NEWS (Release): Mention this.
	Requested by Nicolas Boos

2025-02-01  Jim Meyering  <meyering@meta.com>

	maint: reflect gnulib module renamings
	* bootstrap.conf: Some gnulib modules are now deprecated, in
	favor of new names with a "-h" suffix (and stdbool->bool).
	Induce this change with the following:
	  re='inttypes|signal|stdckdint|stdint|sys_types|sys_wait|unistd'
	  perl -pi -e 's{^('"$re"')$}{$1-h};s{^stdbool$}{bool}' bootstrap.conf
	Then, sort the module names.

	build: update gnulib to latest; and update bootstrap

2025-01-05  Jim Meyering  <meyering@meta.com>

	doc: rewrite the "Unusual File Names" section
	* doc/diffutils.texi (Unusual File Names): Rewrite to reflect
	that file names with e.g., NL and TAB are now quoted.
	Reported by Matěj Cepl in <https://bugs.gnu.org/68695>.

2025-01-05  Bruno Haible  <bruno@clisp.org>

	diff: Fix failure of --no-dereference option (regression 2023-07-01)
	* configure.ac: Move system-related tests closer together. Define
	O_PATH_SUPPORTS_FSTAT if O_PATH exists and is supported by fstat().
	* src/diff.c (O_PATHSEARCH): Don't use O_PATH if it is defined but not
	supported by fstat().

	doc: reference continuous integration URLs
	* README-hacking (Continuous integration): New section:
	list the gitlab and github CI links.

2025-01-03  Jim Meyering  <meyering@meta.com>

	maint: update all copyright dates via "make update-copyright"

	build: update gnulib to latest

2024-10-13  Collin Funk  <collin.funk1@gmail.com>

	maint: use Gnulib's stat-time over our own version
	* bootstrap.conf (gnulib_modules): Add stat-time.
	* configure.ac: Remove check for the st_blksize in struct stat.
	* src/system.h: Include stat-time.h.
	(STAT_BLOCKSIZE): Remove definition.
	* src/analyze.c (diff_2_files):
	* src/cmp.c (main):
	* src/diff3.c (read_diff):
	* src/io.c (sip): Use ST_BLKSIZE instead of STAT_BLOCKSIZE.

2024-09-10  Jim Meyering  <meyering@meta.com>

	maint: avoid old-FSF-address syntax-check failure
	* man/help2man: Update to help2man-1.48.5, but merging in the
	latest #!/usr/bin/env change. Bruno Haible reported that it
	failed a new gnulib syntax-check due to an old FSF mailing
	address in https://bugs.gnu.org/73139

2024-07-22  Bruno Haible  <bruno@clisp.org>

	build: Fix use of perl on Guix, FreeBSD, NetBSD
	* man/help2man: Search for perl in $PATH.

	build: Generate programs' man pages in the source directory, per GCS
	* man/Makefile.am ($(dist_man1_MANS)): Generate the *.1 files in
	$(srcdir), not in the build dir.

2024-07-21  Bruno Haible  <bruno@clisp.org>

	build: Fix a build failure in a VPATH build
	* src/Makefile.am (cmp.$(OBJEXT) etc.): Depend on version.h.

2024-07-15  Paul Eggert  <eggert@cs.ucla.edu>

	maint: adjust to Gnulib -Wsystem-headers change
	* configure.ac (WERROR_CFLAGS): No need to disable
	-Wsystem-headers as Gnulib no longer enables it by default.

	build: update gnulib submodule to latest

2024-07-04  Jim Meyering  <meyering@meta.com>

	build: update gnulib to latest; and update bootstrap

2024-07-04  Collin Funk  <collin.funk1@gmail.com>

	maint: import tests/init.sh from Gnulib during bootstrap
	* bootstrap.conf (bootstrap_post_import_hook): Use gnulib-tool
	--copy-file to import tests/init.sh.
	* tests/init.sh: Remove file.
	* .gitignore (/tests/init.sh): Add entry.

2024-06-23  Collin Funk  <collin.funk1@gmail.com>

	tests: don't fail when --program-transform-name is used
	Problem reported by Jun T <https://bugs.gnu.org/48062>.
	* tests/diff3: Use --diff-program=diff since --program-transform-name
	is applied after install.
	* tests/help-version (sdiff_setup, diff3_setup): Likewise.

2024-06-19  Paul Eggert  <eggert@cs.ucla.edu>

	diff: avoid memory leak with --color-palette
	Problem found indirectly by Coverity, reported by Wasser Mai
	(Bug#71535).  Although the Coverity report was wrong, there was a
	different potential memory leak nearby.  Fix the problem by
	modifying the string in place, avoiding the need to call malloc.
	* src/util.c (color_ext_list, struct color_ext_type):
	Remove.  Not needed, as the list wasn’t used.
	All uses removed.
	(get_funky_string): Omit last argument output_count, as it’s
	easily calculated by caller.  This lets us call this function
	when we don’t care about the count.
	(color_palette): Now char *, not char const *, since we
	now update through it.
	(set_color_palette): Likewise.
	(parse_diff_color): Process color palette into itself, to avoid
	unnecessary malloc and free calls.  This pacifies Coverity, saves
	a bit of space in the normal case, and avoids a memory leak in
	some cases.  Do not process the palette twice, as its memory
	has been modified and this function had no effect on the
	color indicators the second time.

	maint: update .gitignore to add lib/stdbit.h

2024-06-11  Paul Eggert  <eggert@cs.ucla.edu>

	diff: port to FreeBSD, NetBSD
	Problem reported by Bruno Haible <https://bugs.gnu.org/71486>.
	* src/diff.c (NOFOLLOW_SYMLINK_ERRNO): New constant.
	(compare_files): Use it instead of ELOOP.  When it is not ELOOP,
	treat ELOOP as a failure in resolving the parent directory;
	this saves a syscall in some situation.

2024-06-11  Bruno Haible  <bruno@clisp.org>

	tests: Fix ignore-case failure on several platforms
	* tests/ignore-case: Don't compare 'Ⓐ' with 'ⓐ'; this doesn't work on
	NetBSD 10.0 and Solaris 11.4. Don't compare 'Ꞻ' with 'ꞻ'; this doesn't
	work on CentOS 7, macOS, and Solaris 11 OmniOS.

2024-06-11  Paul Eggert  <eggert@cs.ucla.edu>

	maint: port ‘make distcheck’ to Ubuntu 24.04
	* configure.ac: Don’t use -Wsystem-headers, as <stdbit.h>
	uses static functions that couldn’t be called from
	extern inline functions if they were in user code.

	maint: pacify ‘make sc_tight_scope’
	Problem reported by Bruno Haible <https://bugs.gnu.org/71455>.
	* src/system.h (same_file, stat_size): Add ‘extern’.

	maint: port to birthtime platforms
	Problem reported by Bruno Haible <https://bugs.gnu.org/71456>.
	* src/system.c (same_file): Fix typo on platforms with birthtime.

2024-05-21  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2024-05-16  Paul Eggert  <eggert@cs.ucla.edu>

	maint: adjust to Gnulib stdbit splitup
	* bootstrap.conf (gnulib_modules): Remove stdbit; add stdc_bit_width.

	build: update gnulib submodule to latest

2024-05-15  Paul Eggert  <eggert@cs.ucla.edu>

	maint: move same_file and stat_size into system.c
	Now that we have a system.c, there’s little point to these
	being extern inline functions.
	* src/system.c (same_file, stat_size): Move here from system.h,
	and make them ordinary extern functions.
	(proc_dev, symlink_size_ok): Now static, and private to their
	functions.
	* src/system.h (same_file, stat_size): Now just decls.

	build: update gnulib submodule to latest

2024-05-14  Paul Eggert  <eggert@cs.ucla.edu>

	maint: be less fancy when defining extern vars
	Bug reported by Bruno Haible in <https://bugs.gnu.org/70951>.
	I never did like the XTERN macro and its descendants, as this
	“extension” to C causes more confusion than it cures, so let’s
	just get rid of it and use plain ‘extern’.
	* cfg.mk (_gl_TS_extern): Remove XTERN, SYSTEM_EXTERN.
	* src/Makefile.am (cmp_SOURCES, diff3_SOURCES, sdiff_SOURCES)
	(diff_SOURCES): Add system.c.
	* src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c (SYSTEM_INLINE):
	Remove.
	* src/diff.c: Define vars declared in diff.h.
	* src/diff.h (DIFF_EXTERN): Remove.  All uses removed.
	Just use ‘extern’ when declaring extern vars.
	* src/system.h (SYSTEM_EXTERN): Likewise.
	* src/system.c: New file.

	build: update gnulib submodule to latest

2024-05-12  Paul Eggert  <eggert@cs.ucla.edu>

	maint: pacify GCC 14 -Wmissing-variable-declarations
	* src/Makefile.am (version.c): Have it include version.h,
	so that it checks its own interface.
	* src/diff.c (DIFF_INLINE): Define this instead of GDIFF_MAIN,
	for consistency with SYSTEM_INLINE.
	* src/diff.h (DIFF_EXTERN): New macro, replacing XTERN.
	All uses changed.  Adjust to GDIFF_MAIN→DIFF_INLINE change.
	* src/system.h (SYSTEM_EXTERN): Now takes an argument.
	All uses changed.

2024-05-11  Paul Eggert  <eggert@cs.ucla.edu>

	diff: prefer stdbit to count-leading-zeros
	stdbit.h is standardized in C23, so use that instead of
	the GNU-specific count-leading-zeros module.
	* bootstrap.conf (gnulib_modules): Remove count-leading-zeros.
	Add stdbit.
	* src/system.h: Include stdbit.h instead of count-leading-zeros.h.
	(floor_log2): Implement via stdc_bit_width instead of via
	count_leading_zeros_ll.

	maint: update bootstrap to Gnulib version

	build: update gnulib submodule to latest

2024-05-09  Paul Eggert  <eggert@cs.ucla.edu>

	diff: improve GCC 13.3’s static checking
	* src/io.c (slurp): GCC bug 110014 should be fixed in GCC 13.3.

2024-02-18  Paul Eggert  <eggert@cs.ucla.edu>

	diff: restrict scope of GCC bug 110014 workaround
	* src/io.c (slurp): Work around GCC bug 110014 only if GCC 13,
	since it’s reportedly fixed in GCC 14.

2024-01-05  Jim Meyering  <meyering@meta.com>

	maint: make update-copyright

	build: update gnulib to latest; also update bootstrap

	build: suppress -Wmaybe-uninitialized for one function
	* src/sdiff.c (edit): Suppress gcc's -Wmaybe-uninitialized warning
	for this function. Whenever "cmd1 == 'e'", cmd2 **is** initialized.

2023-09-20  Paul Eggert  <eggert@cs.ucla.edu>

	diff: go back to C quoting for diff -c/-u headers
	Gleb Fotengauer-Malinovskiy reported <https://bugs/gnu/org/66095>
	that the recent change to quoting style broke GNU patch.
	* src/util.c: Include quotearg.h.
	(current_name): New static var, replacing the the old
	current_name0 and current_name1.  All uses changed.
	(begin_output): Go back to quoting file names for C,
	not for the shell, when they contain troublesome characters.
	This is not a simple revert, as the revised code handles
	multi-byte characters even in non-UTF-8 locales.
	* tests/filename-quoting: Revert previous change to this file.

	build: update gnulib submodule to latest

2023-09-16  Jim Meyering  <meyering@meta.com>

	build: avoid new build failure
	* src/util.c (output_1_line): Append a semicolon to "default:"
	label, now that the following line is a declaration. Avoids this:
	  error: a label can only be part of a statement and a declaration is\
	  not a statement

2023-09-16  Paul Eggert  <eggert@cs.ucla.edu>

	maint: fix NEWS typos

	diff: tune when O_PATH fails with ELOOP
	* src/diff.c (compare_files): If openat (..., "a/b/.../e/f",
	O_PATH | ...) fails with ELOOP, one of a, a/b, ..., a/b/.../e
	must be a symlink loop; a/b/.../e/f cannot itself be a symlink loop.
	So in this case fail immediately rather than following up with
	fstatat (..., "a/b/.../e/f", ..., AT_SYMLINK_NOFOLLOW).

	diff: tune 'diff --no-dereference --no-file-name-case SYMLINK DIR'
	* src/diff.c (compare_files): If find_dir_file_pathname tells
	us the file type, use that info to avoid unnecessary calls
	to openat.
	* src/dir.c (find_dir_file_pathname): New arg DETYPE.  All uses changed.

2023-09-15  Paul Eggert  <eggert@cs.ucla.edu>

	maint: fix comment typo

2023-09-15  Gleb Fotengauer-Malinovskiy  <glebfm@altlinux.org>  (tiny change)

	diff: fix regression affecting the counting of diff context lines
	This regression was introduced on 2023-05-22 in commit
	v3.10-9-gda1697dcb6 ("diff: C99 decl style in context.c") during a code
	style change.

	This regression was discovered using the GNU patch testsuite:
	FAIL: preserve-c-function-names
	FAIL: reject-format

	 * src/context.c (minus_prefix_lines): Initialize with a reversed value.

2023-09-15  Paul Eggert  <eggert@cs.ucla.edu>

	diff: publish attributes
	* src/diff.h (translate_line_number, find_change):
	Move attribute here ...
	* src/util.c: ... from here.

2023-09-13  Paul Eggert  <eggert@cs.ucla.edu>

	diff: respond faster to write failures
	* src/util.c (output_1_line): Check for signals even
	if there is a write failure, for faster response when
	hammering on /dev/full etc.

	maint: be clearer about when ctype is needed
	Include <ctype.h> and <c-ctype.h> only in modules where needed.
	* src/cmp.c, src/context.c, src/diff.c, src/diff3.c, src/ifdef.c:
	* src/sdiff.c: Include <c-ctype.h>.
	* src/io.c: Include <ctype.h>.
	* src/system.h: Do not include either <ctype.h> or <c-ctype.h>.

	maint: diff no longer uses isblank directly
	* bootstrap.conf (gnulib_modules): Remove isblank.

2023-09-12  Paul Eggert  <eggert@cs.ucla.edu>

	diff: improve util.c multi-byte handling
	* bootstrap.conf (gnulib_modules): Add c32isprint.
	* src/util.c: Include mcel.h.
	(output_1_line): Return immediately on output error.
	Scan multi-byte characters and count their widths.
	(analyze_hunk): Ignore multi-byte white space too.

	sdiff: port to odd isspace locales
	* src/sdiff.c (skip_white): Use c_isspace, not isspace.
	We are parsing diff output, and c_isspace is better here.

2023-09-07  Paul Eggert  <eggert@cs.ucla.edu>

	diff: port --no-dereference changes to non-O_PATH
	This fixes a recently-introduced portability bug
	when running on platforms like Solaris 10 that lack O_PATH.
	* src/diff.c (compare_files): On platforms without O_PATH,
	when running 'diff --no-dereference symlink dir' do not
	report an error merely because dir/symlink is a symbolic link
	and cannot be opened for reading.

	maint: switch to gnulib mcel
	Drop diffutils-specific library code that has been moved into Gnulib.
	* gl/lib/exclude.c, gl/lib/mbscasecmp.c, gl/lib/mcel.c:
	* gl/lib/mcel.h, gl/modules/mcel, gl/modules/mcel-prefer:
	* gl/modules/mcel-tests, gl/tests/test-mcel.c:
	Remove; now taken from Gnulib.

	build: update gnulib submodule to latest

2023-08-30  Paul Eggert  <eggert@cs.ucla.edu>

	maint: define GNULIB_MBRTOC32_REGULAR
	* configure.ac (GNULIB_MBRTOC32_REGULAR): Define.
	diffutils itself already assumes this, so it might as well
	assume it in Gnulib code as well.

2023-08-24  Paul Eggert  <eggert@cs.ucla.edu>

	diff: port mcel.h designated initializers to C99
	* gl/lib/mcel.h (mcel_ch, mcel_err): Use C-standard notation
	for designated initializers, instead of a GNU extension.

2023-08-22  Paul Eggert  <eggert@cs.ucla.edu>

	maint: pacify ‘make syntax-check’
	* cfg.mk: Update exclude_file_name_regexp lists.

2023-08-21  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

	diff: avoid mbuiter
	* bootstrap.conf (avoided_gnulib_modules):
	Avoid mbuiter.
	* gl/lib/exclude.c: New file, with an mcel option.

	diff: modularize and tune mcel code
	Go back to a single mcel module, instead of trying to break it up
	into ucore and mcel pieces, as breaking it up hurt performance.
	Use gnulib-tool’s --local-dir to create diffutils-specific modules
	for mcel; the idea is that this will eventually migrate into Gnulib.
	* bootstrap.conf (avoided_gnulib_modules): Add mbuiterf.
	(gnulib_modules): Add mbscasecmp, mcel-prefer.
	(gnulib_tool_option_extras): Add --local-dir=gl to pick up new files.
	* cfg.mk (exclude_file_name_regexp--sc_prohibit_doubled_word):
	Do not exclude now-removed files lib/ucore.c, lib/ucore.h.
	* lib/Makefile.am: Adjust to use of modules.
	(noinst_HEADERS): Remove mcel.h, ucore.h.
	(libdiffutils_a_SOURCES): Remove mcel.c, mcel-casecmp.c, ucore.c
	* lib/mcel-casecmp.c, lib/ucore.c, lib/ucore.h: Remove.
	* lib/mcel.h: Switch to LGPLv2.1+.  Do not include ucore.h.
	All uses of ucore_t changed back to using char32_t.
	Do what ucore.h used to do: include verify.h, limits.h, stddef.h,
	uchar.h; require config.h, define _GL_LIKELY, _GL_UNLIKELY.
	(MCEl_CHAR_MAX, MCEL_ERR_MIN, MCEL_ERR_MAX): New constants.
	(mcel_t): Switch from single ucore_t c to a char32_t ch and
	unsigned char err.  This has significantly better performance on
	Fedora 38 x86-64.  All uses changed.  Check that unsigned char
	promotes to int.
	(mcel_ch, mcel_err, mcel_cmp, mcel_tocmp): New functions.
	(MCEL_ERR_SHIFT): Rename from MCEL_ENCODING_ERROR_SHIFT.
	All uses changed.
	(mcel_isbasic): Add a _GL_LIKELY to help compilers.  All uses changed.
	(mcel_scan, mcel_scant): Simplify by using mcel_ch, mcel_err.
	(mcel_casecmp): Remove decl.  Callers changed to use mbscasecmp.
	* gl/lib/mcel.c, gl/lib/mcel.h: Rename from lib/mcel.c, lib/mcel.h.
	* gl/lib/mbscasecmp.c: New file.
	* gl/modules/mcel, gl/modules/mcel-prefer, gl/modules/mcel-tests:
	* gl/tests/test-mcel.c:
	New files.
	* src/io.c: Revert use of ucore API.  Use plain c32isspace etc.
	instead of ucore_is.  Use .err instead of ucore_iserr.
	(same_ch_err): Bring back, and use it instead of ucore_cmp.
	* src/side.c (print_half_line):  Use .err instead of ucore_iserr.

	diff: omit ignore_file_name_case test
	* src/dir.c (compare_names): Omit redundant test.

2023-08-20  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix recently-introduced file name case bug
	* src/diff.c (compare_files): When ignoring file name case
	and comparing a file f to a directory d at the top level,
	make sure that if we end up comparing f to d/F then
	don’t mistakenly try to open d/f instead.
	* src/dir.c (compare_collated): Do not worry about
	ignore_file_name_case here.
	(compare_names): Worry about it here instead.
	That way, we do the right thing with the test case.
	* tests/ignore-case: Test for the bug.

2023-08-19  Jim Meyering  <meyering@meta.com>

	maint: avoid syntax-check for doubled word "TO to" in lib/ucore.h
	* cfg.mk (exclude_file_name_regexp--sc_prohibit_doubled_word):
	Also exempt lib/ucore.h.

2023-08-15  Paul Eggert  <eggert@cs.ucla.edu>

	maint: update .gitignore
	* .gitignore: Remove lib/charset.alias, lib/configmake.h,
	lib/ref-add.sed, lib/ref-del.sed.  Add lib/c-file-type.c,
	lib/file-type.h.  Sort.

	diff: simplify multi-byte code (mbcel -> mcel)
	* lib/Makefile.am: Adjust to file renamings and additions.
	* lib/mbcel.c, lib/mbcel.h: Split into two APIs, replacing with ...
	* lib/mcel.c, lib/mcel.h, lib/ucore.c, lib/ucore.h: ... these new files.
	* lib/mcel.h: Simplify by assuming ucore.h is included.
	Check that bytes have 8 bits.
	(MCEL_LEN_MAX, mcel_t, MCEL_INLINE, MCEL_ENCODING_ERROR_SHIFT)
	(mcel_scan, mcel_scant, mcel_scanz, mcel_casecmp):
	Rename from MBCEL_LEN_MAX, mbcel_t, MBCEL_INLINE,
	MBCEL_ENCODING_ERROR_SHIFT, mbcel_scan, mbcel_scanz, mbcel_scant,
	mbcel_casecmp.
	(mcel_t): New member c, replacing old members ch and err.
	All uses changed.
	(MBCEL_UCHAR_FITS, MBCEL_UCHAR_EASILY_FITS): Remove.
	All uses removed.  No longer needed now 8-bit bytes are assumed.
	(MCEL_ENCODING_ERROR_SHIFT): Check that it matches UCORE_ERR_MIN.
	(mcel_isbasic): New function.  Use it where appropriate.
	(mbcel_cmp, mbcel_casecmp): Remove; replaced by ucore_cmp,
	ucore_tocmp.  All uses changed.
	* lib/mcel-casecmp.c: Rename from lib/mbcel-strcasecmp.c.
	Include mcel.h instead of mbcel.h.
	(mcel_casecmp): Rename from mbcel_strcasecmp.  All uses changed.
	Assert that UCHAR_MAX <= INT_MAX, as POSIX requires,
	and simplify code accordingly.  Use mcel rather than mbcel.
	* lib/ucore.h: Include verify.h.
	(ucore_t): New type.
	(UCORE_CHAR_MAX, UCORE_ERR_MIN, UCORE_ERR_MAX, UCORE_C32_SAFE):
	New constants.  Check that information is not lost by encoding
	errors as integers; this is a weaker test than CHAR_BIT == 8.
	(ucore_iserr, ucore_is, ucore_to): New functions.
	(ucore_cmp, ucore_tocmp): New functions, replacing the old
	mbcel_cmp, mbcel_casecmp.  All uses changed.
	* src/dir.c, src/io.c, src/side.c: Use mcel rather than mbcel.
	* src/io.c (same_ch_err): Remove.  All uses replaced by ucore_cmp.

2023-08-14  Paul Eggert  <eggert@cs.ucla.edu>

	diff: improve symlink handling, avoiding a race
	* bootstrap.conf (gnulib_modules): Add c-file-type
	and remove file-type.
	* po/POTFILES.in: Add lib/c-file-type.c, remove lib/file-type.c
	* src/diff.c (O_PATH_DEFINED): New constant.
	(detype_from_mode): Remove; no longer used.
	(dir_p): Go back to the old way of using S_ISDIR.
	(compare_prepped_files): Use filetype and stat macros, not detype.
	Pass symlink fd and "" to careadlinkat if available, as that
	avoids a race.  Test for dir vs file earlier, so that a missing
	file is treated consistently with dir/file vs file.
	(compare_files): New arg DETYPE replacing the old DETYPE0 and DETYPE1.
	All uses changed.  st_size for nonexistent files is 0, not -1.
	Set up .filetype, not .detype, as .filetype is finer-grained.
	Open symlinks with O_PATH on GNU/Linux, since we can then
	use readlinkat on the resulting file descriptor and this
	avoids a race.
	* src/diff.h (struct file_data): Remove detype member.
	Add filetype member; it’s finer-grained.  All uses changed.
	* tests/no-dereference: Add test that the previous commit failed.

	tests: fix comment numbering
	* tests/no-dereference: Omit comment numbers that didn’t correspond
	to test case ordering.

	build: update gnulib submodule to latest

	diff: simplify compare_files statting
	* src/diff.c (compare_files): Simplify the test for whether to get
	file status.  Although this change means diff sometimes will call
	fstat or fstatat when not needed, these occasions are so rare that
	the optimization is not worth the code complexity.

	diff: refactor compare_files
	Break out a good chunk of the body of compare_files into
	a new function compare_prepped_files.  This simplifies
	indenting and code slightly.
	* src/diff.c (compare_prepped_files): New function, taken
	from compare_files.
	(compare_files): Use it.

	diff: report special file major+minor
	* bootstrap.conf (gnulib_modules): Add sys_types,
	for MAJOR_IN_MKDEV and MAJOR_IN_SYSMACROS.
	* src/diff.c (major, minor): New macros or functions.
	Include <sys/mkdev.h> or <sys/sysmacros.h> for them.
	(compare_files): Output major and minor device numbers
	for special files that differ.

2023-08-11  Paul Eggert  <eggert@cs.ucla.edu>

	diff,cmp: tighten up same-file checks
	* src/cmp.c (main):
	* src/diff.c (compare_files):
	* src/dir.c (dir_loop):
	same_file returns bool, not int, so remove "0 <"s that date back
	to when it returned an int.  Remove uses of same_file_attributes.
	* src/system.h (same_file): Now an inline function not a macro.
	Tighten up comparison rules a bit, by ignoring attributes of
	special files whose st_rdev are the same, and by considering
	any birthtime differences to be definitive.  Do all the work
	that same_file_attributes used to do.  Update commentary.
	(same_file_attributes): Remove.  All uses removed.

	maint: tighten stat_size arg type
	* src/system.h (stat_size): Arg is now pointer to const.

2023-08-08  Paul Eggert  <eggert@cs.ucla.edu>

	cmp,diff,diff3,sdiff: quote more consistently
	* lib/diagnose.c, lib/diagnose.h: New files.
	* lib/Makefile.am (noinst_HEADERS, libdiffutils_a_SOURCES):
	Add them.
	* po/POTFILES.in: Add lib/diagnose.c.
	* src/analyze.c, src/cmp.c, src/diff3.c, src/dir.c:
	* src/sdiff.c, src/util.c:
	Include diagnose.h.
	* src/analyze.c (briefly_report, diff_2_files):
	* src/cmp.c (usage, main, cmp):
	* src/diff.c (add_regexp, summarize_regexp_list, main, compare_files):
	* src/diff3.c (usage, process_diff, scan_diff_line):
	* src/dir.c (diff_dirs):
	* src/sdiff.c (usage, ck_fopen, main, edit):
	* src/util.c (perror_with_name, begin_output):
	Quote file names or regexps with squote.
	* src/cmp.c, src/diff.c, src/diff3.c, src/dir.c, src/sdiff.c:
	Include quote.h.
	* src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c (try_help):
	Remove; now in diagnose.c.
	* src/cmp.c (specify_ignore_initial, main, cmp):
	* src/diff.c (main, specify_value, specify_colors_style):
	* src/diff3.c (main, read_diff):
	* src/dir.c (compare_collated):
	* src/sdiff.c (check_child_status, main):
	* src/util.c (finish_output):
	Quote strings with ‘quote’ or ‘quote_n’.
	* src/system.h (EXIT_TROUBLE): Remove; now in diagnose.h
	and now an enum.
	* src/util.c (c_escape_char, c_escape):
	Remove, as we now use squote.
	* tests/cmp, tests/filename-quoting, tests/invalid-re:
	Adjust to match new behavior.

	diff: try lseek on special files
	* src/diff.c (compare_files): It is OK to try lseek on special
	files, as failures are no-ops.  Treat failures as an indication
	that the file position is irrelevant.

	cmp: lseek need not succeed on special files
	* src/cmp.c (main): Do not report an error if lseek returns -1,
	as it is OK if the file is not seekable and none of the other
	lseek errors seem to be relevant.  This reverts my June 21 commit.

	diff: clarify /proc code
	* src/system.h (care_about_symlink_size): New macro.
	(stat_size): Use it. Do the simple checks (requiring no syscalls)
	first.  Although it now makes no difference, remove the S_ISREG (mode)
	check from the /proc test; this is clearer as /proc files need not be
	regular files.

	diff: output symlink contents when they differ
	* bootstrap.conf (gnulib_modules): Add quote.
	* src/diff.c: Include quote.h.
	(compare_files): Print contents of symlinks that differ,
	and quote their names and contents.
	* src/system.h (symlink_size_ok): Remove.
	(stat_size): Don’t worry about symlink sizes.
	* tests/no-dereference: Adjust tests to match new behavior.

2023-08-06  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix some behavior on unreadable input
	This fixes a bug I recently introduced.
	* src/diff.c (compare_files): Set and use openerr to avoid
	the need for a doomed second attempt at openat.
	Don’t insist on openat succeeding before trying fstatat.
	Unless openat fails with ENOENT, ENOTDIR, ELOOP, EOVERFLOW, ENAMETOOLONG
	it’s possible for it to fail even when fstatat would succeed.
	ENOTDIR also means the file does not exist.
	However, do not worry about EBADF as that is no longer possible
	now that diff uses xstdopen.  When checking whether a file should
	be considered to be nonexistent, do not require the other file
	desc to be UNOPENED or STDIN_FILENO; all that is needed is
	for the other file to not have an ENOENT or ENOTDIR failure.
	* src/diff.h (struct file_data): New member openerr.
	(OPEN_FAILED): New constant.
	* tests/new-file: Add a regression test to catch the bug
	fixed by the above.

	diff: fix recent -N regression
	* src/diff.c (compare_files): Fix recent regression, by
	looking at cmp.file[1 - f].err rather than cmp.file[1 - f].desc.
	Also, do not bother checking for EBADF, as that’s no longer
	possible now that diff uses xstdopen.

2023-08-05  Paul Eggert  <eggert@cs.ucla.edu>

	diff: minor errno performance tweak
	* src/diff.c (get_errno): New function.
	(compare_files): Use it.

	diff: prefer openat+fstat more often
	This closes some more races, by using openat+fstat instead
	of fstatat+openat which can get confused by some other process
	renaming files in the meantime.  Not all races are closed of course.
	* bootstrap.conf (gnulib_modules): Add d-type.
	* src/diff.c (errno_encode, errno_decode): Remove, as file
	descriptors are no longer portmanteau variables.  All uses removed.
	(detype_from_mode): New function.
	(dir_p): Use detype, not stat.st_mode.
	(compare_files): New args DETYPE0 and DETYPE1.  All uses changed.
	Update detype and err as new info arrives.
	Adjust to desc's new use (no longer encodes errno).
	Do not ignore lseek failures on regular files.
	Prefer openat+fstat to fstatat+openat when detype shows that it's safe,
	and avoid both fstat and fstatat if detype suffices.
	Use ‘error’ with errno value rather than setting error
	and then calling perror_with_name.  Coalesce two of these
	error diagnostics into one by moving an error check before
	the diagnostic is output.  Coalesce two calls to diff_dirs.
	Print file type based on detype if available,
	in case neither fstat nor fstatat was called.
	* src/diff.h (enum detype): New type.
	(struct file_data): New slots err, detype.
	(NONEXISTENT, UNOPENED): Renumber so that -1 stands for open failed.
	* src/dir.c (HAVE_STRUCT_DIRENT_D_TYPE): Default to false.
	(dir_read): Return to caller the d_type, if available.
	 	(diff_dirs): Pass detype to compare_files.

	maint: use O_CLOEXEC on streams
	* bootstrap.conf (gnulib_modules): Add fopen-gnu, for the "e" flag.
	* src/diff3.c (main):
	* src/sdiff.c (main, edit):
	Use the "e" flag.

	maint: use O_CLOEXEC
	* src/cmp.c (main):
	* src/diff.c (compare_files):
	* src/dir.c (dir_read):
	Use O_CLOEXEC when opening files that need not be shared with
	child processes.

	diff: tiny tweak to compare_files performance
	* src/diff.c (compare_files): Compare ints, not strings.

	diff: simplify diff_dirs API
	* src/diff.c (compare_files):
	Now extern, not static,	so that diff_dirs can call it.
	* src/dir.c (diff_dirs): Remove arg HANDLE_FILE, since it was
	always compare_files.  Just call compare_files directly.
	All uses changed.

	diff: simplify diff_dirs
	* src/dir.c (diff_dirs): Simplify and help the compiler a bit.

	diff: tune errno handling
	* src/diff.c (errno_encode): Add dassert to help debugging,
	and help the compiler when not debugging.

	diff: avoid a race when opening files
	* src/diff.c (O_PATHSEARCH): New constant.
	(compare_files): Prefer openat+fstat to fstatat+openat,
	as it avoids a race and should be a bit faster.

2023-08-01  Jim Meyering  <meyering@meta.com>

	maint: avoid new syntax-check failures
	* cfg.mk (_gl_TS_extern): Add SYSTEM_EXTERN to the list.
	* src/system.h (stat_size): Hoist function name onto the
	preceding line, to placate syntax-check rule.

2023-07-30  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fail faster in odd --ignore-file-name-case usage
	* src/diff.c (compare_files):
	Fail faster with ‘diff --ignore-file-name case - .’.

	maint: be more careful about st_size
	* src/cmp.c (main): st_size == -2 now means the rest of
	the stat buf is unspecified; st_size == -1 now merely
	means st_size itself is unspecified.  All uses changed.
	* src/analyze.c (diff_2_files):
	* src/diff.c (compare_files):
	Trust st_size == 0, as this is now reliable.
	* src/diff.c (compare_files): Don’t always trust st_size of /proc
	files and symlinks.
	* src/system.h (SYSTEM_EXTERN): New macro.
	(proc_dev, symlink_size_ok): New vars.
	(stat_size): New function.

2023-07-28  Paul Eggert  <eggert@cs.ucla.edu>

	diff: omit no-longer-safe optimization
	* src/diff.c (compare_files): Remove optimization for size-zero
	files that is no longer valid for unusual combinations like ‘touch
	mt; diff /proc/kmsg mt’ where one file is an empty regular file
	and the other is an unreadable /proc file with st_size zero but
	where the actual size is nonzero.

2023-07-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: tweak context timestamp buffer size
	* src/context.c (print_context_label): Use a more conservative
	upper bound for timestamp length.  In practice this change
	makes no difference: it’s more for documentation.

2023-07-25  Paul Eggert  <eggert@cs.ucla.edu>

	diff: stop using sprintf
	The calls to sprintf are not needed any more, since the resulting
	string is now immediately passed to fprintf.
	* src/context.c (print_context_label): Redo to call

	maint: translate openat-die.c
	* po/POTFILES.in: Re-add lib/openat-die.c.

	diff3: simplify by assuming !GCC_LINT
	GCC's static checks no longer seem to warn about the code
	protected by GCC_LINT, so remove its last uses, which were in diff3.
	(Or perhaps it was valgrind or gcc -fsanitize=address leak
	checking instead?  But in that case there are other false
	positives and we don’t worry about them either.)  This code was
	problematic anyway when introduced (as witness the corresponding
	test case) and it slowed diff3 down a bit.
	* configure.ac (GCC_LINT): Remove.  All uses removed.
	* src/diff3.c: Simplify by assuming !GCC_LINT.

	diff: simplify SIGSTOP/SIGTSTP porting
	* src/util.c (SIGSTOP, SIGTSTP): Default to 0.
	(process_signals, is_tstp_index): Simplify by using the default.
	(sig): Adjust to default.

2023-07-25  Bruno Haible  <bruno@clisp.org>

	maint: Fix build failures mingw 10 and MSVC 14.30
	* bootstrap.conf (gnulib_modules): Add popen, pclose, readdir,
	readlinkat, sigaction.
	* configure.ac: Don't enable _FORTIFY_SOURCE on mingw.
	* src/util.c (process_signals): If SIGTSTP is not defined,
	stop_signal_count is zero, therefore disable the stop signal processing.
	(sig): If SIGHUP is not defined, don't list it. If SIGPIPE is not
	defined, don't list it.

2023-07-24  Paul Eggert  <eggert@cs.ucla.edu>

	maint: port better to MS-Windows
	Problem reported by Gisle Vanem <https://bugs.gnu.org/64811>.
	* bootstrap.conf (gnulib_modules): Add fstatat, openat.

	diff: compare symbolic links more efficently
	Also, remove dependence on xreadlink.
	* bootstrap.conf (gnulib_modules): Add careadlinkat.
	Remove xreadlink (which depends on careadlinkat).
	* src/diff.c: Include careadlinkat.h, not xreadlink.h.
	(compare_files): Don’t bother to read links if their lengths differ.
	Use careadlinkat instead of xreadlink so that normally malloc need
	not be called.

2023-07-23  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: fix recent off-by-1 error
	* src/cmp.c (cmp): Subtract 1 from byte_number before printing,
	fixing an off-by-one error in the previous patch.

	build: update gnulib submodule to latest

	cmp: remove dependence on inttostr
	* bootstrap.conf (gnulib_modules): Remove inttostr.
	* src/cmp.c: Do not include inttostr.h.
	(cmp): Use C99-style PRIdMAX rather than Gnulib inttostr,
	as PRIdMAX is simpler and (thanks to Gnulib) is portable.

	diff: omit HAVE_STRUCT_STAT_ST_SPARE1
	* src/diff.c (main): Remove reference to macro
	HAVE_STRUCT_STAT_ST_SPARE1, which hasn’t been defined since 2007.

	diff: get current time lazily, via C11
	* bootstrap.conf (gnulib_modules): Remove gettime; add timespec_get.
	* src/context.c (print_context_label): Get current time lazily.
	Use C11 timespec_get rather than older Gnulib gettime function.
	* src/diff.c: Do not include timespec.h.
	(set_mtime_to_now): Remove.  All uses removed.

2023-07-22  Paul Eggert  <eggert@cs.ucla.edu>

	diff: check file attributes more carefully
	* src/system.h: Include stat-time.h, timespec.h.
	* bootstrap.conf (gnulib_modules): Add timespec, for timespec_cmp.
	(same_file_attributes): Check birthtime and ns components too.
	Check attributes earlier if they are more likely to differ.

2023-07-21  Paul Eggert  <eggert@cs.ucla.edu>

	diff: don’t think mbcel_strcasecmp preserves errno
	* configure.ac: Do not check for strcasecoll (which doesn’t exist)
	or stricoll (not worth the porting hassle, as it doesn’t set errno).
	* src/dir.c: Always include mbcel.h, since we now always
	use mbcel_strcasecmp.
	(strcasecoll): Remove
	(compare_collated, diff_dirs): Do the setjump business only when
	not ignoring file name case, since mbcel_strcasecmp doesn’t fail
	and doesn’t set errno.  This fixes a bug in recent changes,
	which incorrectly assumed mbcel_strcasecmp preserves errno.

	* src/dir.c:
	Always include mbcel.h, since we now always compile a call
	to mbcel_strcasecmp.
	(strcasecoll): Remove.  It’s not worth bothering to port to
	Microsoft stricoll’s idiosyncrasies; mbcel_strcasecmp is good enough.
	And nobody ever implemented strcasecoll.

2023-07-21  Paul Eggert  <eggert@cs.ucla.edu>

	diff: simplify qsort comparison function
	* src/dir.c (compare_names_for_qsort): Simplify.

	diff: sort multi-byte file names better
	* bootstrap.conf (gnulib_modules): Add builtin-expect.
	* lib/mbcel-strcasecmp.c: New file.
	* lib/Makefile.am (libdiffutils_a_SOURCES): Add it.
	* lib/mbcel.h (MBCEL_LEN_MAX, MBCEL_ENCODING_ERROR_SHIFT)
	(MBCEL_UCHAR_FITS, MBCEL_UCHAR_EASILY_FITS): New constants.
	(_GL_LIKELY): New macro.
	(mbcel_scan): Use it.  Simplify NetBSD code.
	(mbcel_scant, mbcel_scanz, mbcel_cmp, mbcel_casecmp): New functions.
	* src/dir.c (strcasecoll): Move defn here from system.h,
	since only dir.c needs it.  Use mbcel_strcasecmp instead
	of strcasecmp.

	diff: remove diff_dirs ‘volatile’
	* src/dir.c (diff_dirs): Omit ‘volatile’, as it’s no longer
	needed with the current use of setjmp.

2023-07-19  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: remove IF_LINT
	* src/cmp.c (cmp): Redo to avoid the need for IF_LINT, while still
	pacifying GCC.  The machine code is a bit smaller too.  The price
	is a portmanteau variable, but it’s worth it.
	* src/system.h (IF_LINT): Remove.

	diff: simplify away an ‘IF_LINT (volatile)’
	* src/dir.c (find_dir_file_pathname): Simplify.  There is no
	longer a need for volatile or setjmp, now that dir_read does all
	the tricky sorting and longjmping.

	diff: improve -S dir-reading performance
	* src/dir.c (dir_read): New args STARTFILE and STARTFILE_ONLY,
	to avoid unnecessary allocation and copying.  All uses changed.
	* tests/starting-file: New test.
	* tests/Makefile.am (TESTS): Add it.

	diff: fix recently-introduced &noparent bug
	* src/dir.c (diff_dirs, dir_loop): The ‘parent’ member is now
	&noparent (instead of null) if there is no parent.  Patch
	a couple of uses that were missed earlier.

2023-07-18  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix mbcel bug on NetBSD
	* lib/mbcel.h (mbcel_t):
	Fix bug on NetBSD as I read its code incorrectly earlier.
	Problem reported by Bruno Haible in:
	https://lists.gnu.org/r/bug-gnulib/2023-07/msg00085.html
	Mostly for documentation, use _GL_ATTRIBUTE_MAY_ALIAS to remind
	compiler not to rely on strict C semantics for unions.

	maint: convert source from non-UTF-8
	* po/en.po: Convert from Latin-1 to UTF-8.
	This was the only remaining file under Git control
	that still used an encoding other than UTF-8.

	diff: use openat, fstatat when recursive
	This should improve performance when doing recursive comparisons.
	Currently there is no attempt to avoid file descriptor exhaustion,
	just as previously there is no attempt to avoid file names
	that provoke ENAMETOOLONG.  Because of this change, ‘diff - A/B’
	now works correctly when standard input is a directory.
	* .gitignore: Add lib/dirent.h.
	* bootstrap.conf (gnulib_modules): Add fdopendir.
	* src/diff.c (main): Initialize noparent’s desc to AT_FDCWD.
	(compare_files): Use fstatat with parent directory’s file
	descriptor and relative name, instead of lstat or stat.
	Likewise for openat and open.
	* src/diff.h (struct file_data): New member ‘dirstream’.
	(struct comparison): The ‘parent’ member is now &noparent (instead
	of null) if there is no parent.  All uses changed.
	(curr): New toplevel variable, replacing ‘files’.  All uses changed.
	* src/dir.c: Include dirname.h, for last_component.
	(dir_read): New arg PARENTDIRFD.  Arg DIR is no longer
	pointer-to-const since DIR->desc and DIR->dirstream are now
	updated.  Use PARENTDIRFD to open the directory via
	opendat+fdopendir instead of via opendir.  Update new dirstream
	component instead of closing the directory, since it’s now the
	caller’s responsibility to close the directory because callers now
	want the file descriptor.  All callers changed.
	(diff_dirs): First arg CMP is no longer pointer-to-const since
	CMP->file is updated by dir_read.  All callers changed.
	(find_dir_file_pathname): First arg is now struct file_data *,
	not merely a file name.  All callers changed.
	* tests/stdin: Test new behavior when stdin is a directory.

	maint: stop exempting lib/mbcel.h
	* cfg.mk (exclude_file_name_regexp--sc_GPL_version): Remove.

2023-07-18  Jim Meyering  <meyering@meta.com>

	maint: avoid syntax-check failure
	* po/POTFILES.in: Remove openat-die.c.
	It is no longer used.  Reported by Bruno Haible in
	https://lists.gnu.org/r/diffutils-devel/2023-07/msg00018.html

2023-07-17  Paul Eggert  <eggert@cs.ucla.edu>

	doc: document tab behavior better
	* doc/diffutils.texi (Tabs): Document issues with tabs,
	encoding errors, and non-ASCII characters.

	diff: remove find_reverse_change
	This is a minor refactoring and simplification.
	* src/context.c (find_hunk):
	* src/util.c (find_change): Rename locals for clarity.
	(find_reverse_change): Remove.  All uses removed.

	diff: assert-related cleanup
	Regularize how assertions are done by using ‘unreachable’ or a new
	macro ‘dassert’, or by removing unnecessary assertions.
	* src/analyze.c (diff_2_files):
	* src/util.c (get_funky_string, parse_diff_color)
	(set_color_context):
	Prefer unreachable to abort for code where it’s easy to
	see that it cannot be reached.
	* src/context.c (ATTRIBUTE_PURE):
	* src/util.c (print_message_queue):
	Prefer ‘dassert (X);’ to ‘if (!X) abort ();’.
	* src/diff.c: Do not include assert.h; system.h does that if needed.
	(usage): Remove the need for an assert by using fputs and fwrite
	rather than printf.  This is clearer anyway.
	(compare_files): Remove ‘assert’ that hardware will check.
	Prefer dassert to assert.
	* src/ifdef.c (do_printf_spec):
	Prefer dassert to comment.
	* src/system.h (dassert): New macro.  Include assert.h if needed.

	maint: prefer puts to printf
	* src/cmp.c (usage):
	* src/util.c (begin_output):
	Simplify by using puts instead of printf.

	diff: improve dir comments
	* src/dir.c: Improve comments.

	diff: improve NONEXISTENT readability
	* src/diff.c (NONEXISTENT, UNOPENED): Move from here ...
	* src/diff.h: ... to here.
	* src/dir.c (dir_read, diff_dirs): Use name for constants.

	diff: link to LIB32CONV
	* src/Makefile.am (LDADD): Add LIB32CONV; needed for recent
	char32_t changes on some platforms.

	diff: reindent recent changes
	* src/io.c (lines_differ): A bit less indenting.

	maint: translate lib/openat-die.c
	* po/POTFILES.in: Add lib/openat-die.c.

	maint: mbcel.h is LGPL 3 not 2.1
	* lib/mbcel.h: Make it LGPL 3, not 2.1, to pass "make syntax-check".

2023-07-12  Jim Meyering  <meyering@meta.com>

	maint: avoid a new syntax-check failure
	* cfg.mk (exclude_file_name_regexp--sc_GPL_version): Exempt mbcel.h,
	which is GPL-2.1. Remove this exemption if/when mbcel.h moves to gnulib.

2023-07-11  Paul Eggert  <eggert@cs.ucla.edu>

	diff: tweak mbstate_t performance
	* lib/mbcel.h (mbcel_scan): Improve performance when initializing
	an mbstate_t.

2023-07-10  Paul Eggert  <eggert@cs.ucla.edu>

	diff: add mbcel checks, compiler advice
	* lib/mbcel.h: Include limits.h, stddef.h.
	Add static assertions that MB_LEN_MAX has a sane value,
	as the code relies on this.  Help GCC by advising
	it that mbrtoc32 never returns a value between
	MB_LEN_MAX + 1 and (size_t) -1 / 2 inclusive.

2023-07-09  Paul Eggert  <eggert@cs.ucla.edu>

	diff: tweak mbcel_scan performance
	* lib/mbcel.h (mbcel_scan): Check top bit of size
	rather than comparing it to MB_LEN_MAX, as this
	typically lets the compiler generate tighter code.

	maint: fix mbcel comment

	maint: update .gitignore

	diff: count newlines for lines_differ lengths
	* src/io.c (lines_differ): Line lengths now count trailing
	newlines, as this is a bit simpler.  Caller changed.

	diff: refactor lines_differ location
	* src/io.c (lines_differ): Move here ...
	* src/util.c: ... from here, since it needs to be kept consistent
	with find_and_hash_each line anyway, and there is no reason to
	make it an extern function.

	diff: simplify recent --side-by-side changes
	* src/side.c: Include mbcel.h instead of uchar.h.
	(print_half_line): Simplify by using mbcel_scan rather than
	mbrtoc32.  Although this removes support for hypothetical platforms,
	it makes the code easier to follow and a bit more efficient.

	diff: support multi-byte comparison
	* bootstrap.conf (gnulib_modules): Add c32isspace, c32tolower.
	* lib/Makefile.am (noinst_HEADERS): Add mbcel.h.
	(libdiffutils_a_SOURCES): Add mbcel.c
	* lib/mbcel.c, lib/mbcel.h: New files.
	* src/io.c: Include mbcel.h, uchar.h.
	(hash): 2nd arg is now hash_value, not merely unsigned char,
	since the caller might pass a char32_t now.
	(find_and_hash_each_line): Support multi-byte input.
	* src/util.c: Include mbcel.h, uchar.h.
	(lines_differ): New args S1LEN, S2LEN, needed for mbcel_scan.
	Caller changed.  Support multi-byte input.
	* tests/ignore-case: New file.
	* tests/Makefile.am (TESTS): Add it.
	* tests/ignore-tab-expansion: Add UTF-8 test.
	* tests/init.cfg (require_utf8_locale_): New function.
	* tests/side-by-side: Use it.  Add a column-counting test.

2023-07-06  Paul Eggert  <eggert@cs.ucla.edu>

	diff: simplify recent mbrtoc32 improvement
	* src/side.c (print_half_line): Simplify.  Don't worry about
	initializing mbstate until it's needed.  Avoid int overflow if the
	byte sequence represents more than INT_MAX columns.  Avoid need
	for separate TP1 local.

2023-07-06  Bruno Haible  <bruno@clisp.org>

	tests: Add a side-by-side output test
	* tests/side-by-side: New file.
	* tests/Makefile.am (TESTS): Add it.

	diff: Improve handling of mbrtoc32 result
	* src/side.c (print_half_line): When mbrtoc32 has left the mbstate not
	in the initial state, continue calling mbrtoc32.

2023-07-05  Paul Eggert  <eggert@cs.ucla.edu>

	diff: ignore tabs consistently with expanding them
	* src/io.c (find_and_hash_each_line):
	* src/util.c (lines_differ):
	Treat '\0', '\a', '\b', '\f', '\r', '\v' consistently with how
	side.c treats them when expanding them, e.g., backspacing from
	column 1 is a no-op when counting tab columns.
	* tests/ignore-tab-expansion: New test.
	* tests/Makefile.am (TESTS): Add it.

	diff: don’t backspace before first column
	* src/util.c (output_1_line): When expanding tabs, treat backspace
	before column 1 as no-op, since that’s what most devices do.
	* tests/expand-tabs: New test.
	* tests/Makefile.am (TESTS): Add it.

	diff: tweak -y performance for $ @ ` \a
	* src/side.c (print_half_line): Improve performance for '$', '@',
	'`', and '\a' since they also are portable in practice nowadays.

2023-07-05  Bruno Haible  <bruno@clisp.org>

	diff: Fix "diff -y" output
	This fixes a regression from 2023-07-04.

	* src/side.c (print_half_line): Restore the assignment to out_position.

2023-07-04  Paul Eggert  <eggert@cs.ucla.edu>

	doc: mention bug#64461 in NEWS

2023-07-04  Bruno Haible  <bruno@clisp.org>

	diff: Fix output of "diff -l -y" for non-ASCII input files
	* src/side.c (print_half_line): Output the multibyte character to out,
	not stdout.

2023-07-04  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix unspecified mbstate after encoding error
	* src/side.c (print_half_line): Clear mbstate after encoding
	error, since it’s unspecified.

	diff: optimize -y treatment of NUL
	* src/side.c (print_half_line): Treat '\0' like other control
	characters with print width zero.

	diff: fix unlikely intmax_t overflow
	* src/side.c (print_half_line): Avoid undefined behavior if the
	input column position overflows.  Instead, simply stop printing.

2023-06-28  Paul Eggert  <eggert@cs.ucla.edu>

	maint: prefer ‘static_assert’
	Prefer C23-style ‘static_assert’ to traditional Gnulib ‘verify’.
	* bootstrap.conf (gnulib_modules): Add assert-h.
	* src/context.c, src/io.c, src/system.h: Use ‘static_assert’.

	diff: fix xpalloc-related signed integer overflow
	Problem reported by Gisle Vanem <https://bugs.gnu.org/64316>.
	* src/io.c (find_and_hash_each_line):
	Rely on xpalloc to check for integer overflow instead
	of trying to do it ourselves incorrectly, with old code
	that predated the use of xpalloc.
	* src/system.h: Verify that LIN_MAX == IDX_MAX,
	since the code now relies on this.
	* tests/Makefile.am (TESTS): Add bug-64316.
	* tests/bug-64316: New file

	diff: tweak mbrtoc32 use
	* src/side.c (print_half_line): Use more-intuitive
	way to test whether mbrtoc32 found a non-null character.

2023-06-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix xpalloc typo
	Problem reported by Gisle Vanem (Bug#64316).
	* src/dir.c (dir_read): Also set local var cache.

2023-06-26  Paul Eggert  <eggert@cs.ucla.edu>

	maint: pacify "make syntax-check"

	cmp: make -bl locale-independent again
	* src/cmp.c (sprintc): Use c_isprint, not isprint, fixing a bug I
	introduced in 2004.
	* tests/cmp: Test for the bug.

	diff: omit c-ctype.h double-include
	* src/context.c: Don’t include c-ctype.h,
	as system.h does that for us.

	maint: omit unneeded 0 args to ‘open’
	* src/cmp.c (main):
	* src/diff.c (compare_files): Omit third arg 0 to ‘open’.
	This was never necessary, and I suspect was put in only to pacify
	no-longer-relevant compilers.

	diff: avoid ‘if (... = ...)’
	* src/diff.c (compare_files):
	* src/ifdef.c (format_group, print_ifdef_lines):
	* src/io.c (find_and_hash_each_line):
	Don’t put assignments into ‘if (...)’, of ‘switch (...)’,
	as per GNU coding standards.

	cmp: tune 'cmp A B >/dev/null'
	* src/cmp.c (main): Also optimize 'cmp A B >/dev/null'
	when A and B are regular files with different nonzero sizes.
	* tests/cmp: Test this.

	cmp: support -n N with huge N
	* src/cmp.c (bytes): Use INTMAX_MAX, not -1, for “infinity”.
	This simplifies the code and is not a value that can be exhausted
	these days.
	(main, cmp): Treat very large -n values as “infinity”.
	* tests/cmp: Test this.

	cmp: avoid syscall when !S_ISCHR (stdout)
	* src/cmp.c (main): Avoid a 'stat' call in the common case when
	standard output is not a character special device.  This is valid
	because /dev/null is a character special device.

2023-06-25  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: improve offset width calculation
	* src/cmp.c (cmp): When calculating the offset width,
	Don’t attempt to squeeze a file position into an int
	as that might trap or yield the wrong answer.
	Also, treat “negative” file sizes as zero; this can
	happen if the initial file offset is past EOF.

	cmp: work around lseek bugs
	* src/cmp.c (ignore_initial): Now an array of intmax_t not off_t.
	This allows cmp -i N to work better on platforms where intmax_t
	is wider than off_t, N fits in the former and not the latter,
	and the input is not a regular file.  All uses changed.
	(cmp): Instead of seeking to file end when -i N is huge,
	simply pretend that we read zero bytes.  This avoids some
	kernel lseek bugs.

	cmp: do not try to read 2**64 - 1 bytes
	* src/cmp.c (cmp): Do not store a negative value into
	bytes_to_read, as that causes block_read to be passed
	SIZE_MAX as the buffer size.

2023-06-25  Jim Meyering  <meyering@meta.com>

	cmp: avoid new tests/cmp failure
	* src/cmp.c (file_position): Set position to EOF by calling lseek
	with an offset of 0 and SEEK_END, rather than a SEEK_CURR-relative
	offset of the maximum off_t value. The latter would evoke failure on
	fedora 38/glibc-2.37/linux 6.2.15-300.fc38.x86_64:
	  lseek(3, 9223372036854775807, SEEK_CUR) = -1 EINVAL
	The failing test was this (which must now exit 0, but did not):
	  echo a>a;echo b>b; src/cmp -i 99999999999999999999 a b

2023-06-24  Jim Meyering  <meyering@meta.com>

	maint: avoid syntax-check failure
	* NEWS (Bug fixes): Move the two new items from the section
	for already-relesed 3.10 into the section for the next release.

2023-06-24  Bruno Haible  <bruno@clisp.org>

	build: Ensure that makeinfo ≥ 6.8 checks the @menu structure
	See <https://lists.gnu.org/r/bug-texinfo/2023-06/msg00015.html>.

	* doc/Makefile.am (MAKEINFO): New variable.
	* cfg.mk (_makefile_at_at_check_exceptions): New variable.

2023-06-24  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: handle huge -i N with regular files
	* NEWS: Document this.
	* src/cmp.c (specify_ignore_initial):
	If the value exceeds TYPE_MAXIMUM (off_t), set the correspnding
	ignore_initial value to -1 instead of reporting an error.
	(main, cmp, file_position): All uses changed.  Hence a huge value
	will always do the right thing with regular files, which cannot
	contain more than TYPE_MAXIMUM (off_t) bytes.  There still may be
	EOVERFLOW failures reported for non-regular files, though, as
	these can be larger.
	* tests/cmp: Test cmp -i N when N cannot fit into 64 bits.

	cmp: work around Linux tmpfs bug
	* lib/cmpbuf.c: Include inttypes.h, for TYPE_MAXIMUM.
	(block_read): Work around Linux 6.3.8 tmpfs bug.

	cmp: be more robust if lseek fails
	* src/cmp.c (main, cmp): If lseek fails,
	don’t assume the file position is -1.

	cmp: fix -s bug when comparing /proc files
	* NEWS: Mention this.
	* src/cmp.c (main, cmp): Do not trust st_size == 0, as it may
	be a /proc file.
	* tests/brief-vs-stat-zero-kernel-lies: Also test cmp -s.

2023-06-20  Paul Eggert  <eggert@cs.ucla.edu>

	doc: mention new SI prefixes
	* doc/diffutils.texi (cmp Options): Update for new SI prefixes R and Q.
	Simplify the intro to be more like coreutils.

	maint: prefer c_isdigit to ISDIGIT
	c_isdigit is a function supplied by Gnulib, which should
	be a bit better than our own macro.
	* bootstrap.conf (gnulib_modules): Add c-ctype.
	* src/system.h (ISDIGIT): Remove.  All calls replaced by c_isdigit.
	Include <c-ctype.h>, for c_isdigit.

	maint: omit -Wstack-pointer
	* configure.ac (WERROR_CFLAGS): Do not use -Wstack-protector.
	It is not a correctness warning, and it causes a false
	positive on Ubuntu 23.04 x86-64.

2023-06-06  Jim Meyering  <meyering@meta.com>

	build: update gnulib to latest (for maint.mk syntax-check fix)

	maint: avoid new tight-scope syntax-check failure
	* src/system.h (floor_log2): Declare with "SYSTEM_INLINE int"
	on the same line as the function name, to accommodate the
	tight-scope syntax-check rule.
	* cfg.mk (_gl_TS_extern): Add SYSTEM_INLINE to the regexp.

2023-06-06  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

	maint: update .gitignore
	* .gitignore: Add *.rej (for 'patch'), lib/error.c.

	maint: sync bootstrap from Gnulib
	* bootstrap, tests/init.sh: Copy from Gnulib.

	diff: switch from wchar_t to char32_t
	Prefer C11-style char32_t to wchar_t, as char32_t works better on
	platforms where wchar_t is only 16 bits.
	* .gitignore: Add lib/uchar.h.
	* bootstrap.conf (gnulib_modules): Add c32width, mbrtoc32.
	Remove mbrtowc.  Sort.
	* src/side.c: Include uchar.h instead of wchar.h.
	(print_half_line): Use c32width and mbrtowc instead of
	wcwidth and mbrtowc.

	maint: tell Gnulib diffutils is single-threaded
	* configure.ac (GNULIB_EXCLUDE_SINGLE_THREAD)
	(GNULIB_MBRTOWC_SINGLE_THREAD, GNULIB_REGEX_SINGLE_THREAD)
	(GNULIB_WCHAR_SINGLE_LOCALE):
	Define, to improve performance a bit in Gnulib.
	Diffutils is single-threaded and sets locales first.

2023-06-03  Paul Eggert  <eggert@cs.ucla.edu>

	maint: use similar style for parsing options
	This refactors and reindents option-parsing so that the code looks
	similar in all three main programs.
	* src/cmp.c, src/diff3.c, src/sdiff.c (shortopts): New constant.
	(main): Use it.
	* src/diff.c (main): Put local inside loop.

	maint: go back from ‘die’ to ‘error’
	* src/Makefile.am (noinst_HEADERS): Remove die.h.
	* src/die.h: Remove.  All uses of ‘die’ replaced with ‘error’,
	and all includes of die.h removed.
	This reverts commit 2016-10-16T15:43:14Z!meyering@fb.com,
	which is no longer needed now that the Gnulib ‘error’
	module arranges for static checking to work with ‘error’.

	diff: bool, not char, for changed vector
	* src/diff.h (struct file_data.changed): Now bool instead of char.
	This shrinks the size of the code generated on GCC x86-64 by 1.6%.
	Formerly this was char because bool’s size is greater than 1
	on some platforms, but those platforms are no longer of so
	much importance that it’s worth pessimizing on common platforms.
	All uses changed.

	maint: be more specific about 0 and 1
	* src/analyze.c (NOTE_DELETE, NOTE_INSERT)
	(discard_confusing_lines, shift_boundaries)
	(build_reverse_script, build_script, diff_2_files):
	* src/cmp.c (specify_comparison_type, option_help_msgid, main):
	* src/diff.c (main, option_help_msgid):
	* src/diff3.c (main, option_help_msgid, make_3way_diff)
	(using_to_diff3_block, create_diff3_block, process_diff):
	* src/dir.c (dir_read):
	* src/ifdef.c (format_ifdef, format_group, print_ifdef_lines)
	(do_printf_spec, scan_char_literal):
	* src/io.c (binary_file_p):
	* src/sdiff.c (option_help_msgid, lf_snarf, main, trapsigs)
	(untrapsig):
	* src/util.c (message, setup_output, begin_output)
	(finish_output, lines_differ, print_script, print_1_line_nl)
	(change_letter, analyze_hunk):
	Prefer more-specific constants like true, false and nullptr
	to the less-specific 1 and 0.

	maint: switch from propername to propername-lite
	* bootstrap.conf (gnulib_modules): Replace propername with
	propername-lite.
	* src/Makefile.am (LDADD): Remove $(LIBICONV).  Sort.
	* src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c (AUTHORS):
	Use proper_name_lite and gettext instead of proper_name_utf8 and
	proper_name.

	maint: modernize GCC warnings, AC_INIT
	* configure.ac: Pass new args to AC_INIT.
	(gl_GCC_VERSION_IFELSE): New macro, taken from coreutils.
	Modernize GCC warnings to agree more with coreutils.

	maint: remove AM_PROG_CC_C_O cruft
	* bootstrap.conf (buildreq): Require Automake 1.14 instead of 1.12.2,
	since AM_PROG_CC_C_O is obsolete as of 1.14.
	* configure.ac: Don’t use obsolescent AM_PROG_CC_C_O.

	diff: remove CLOSEDIR_VOID cruft
	* configure.ac: Don’t use AC_FUNC_CLOSEDIR_VOID; it’s obsolescent.
	* src/dir.c (dir_read): Simplify by assuming !CLOSEDIR_VOID.

	diff: don’t limit contexts arbitrarily
	* src/context.c (find_hunk):
	Check for overflow when computing non-ignorable threshold.
	* src/diff.c (main): Limit ‘context’ to LIN_MAX since it is a lin.
	* src/system.h (CONTEXT_MAX): Remove.

	diff: calculate log2 faster in io.c
	* src/io.c (find_identical_ends): Use floor_log2 instead
	of computing log base 2 by hand.

	maint: improve floor_log2 comment
	* src/system.h: Document floor_log2 (0).

	maint: use same-inode
	* bootstrap.conf (gnulib_modules): Add same-inode.
	* src/system.h: Include <same-inode.h>.
	(same_file): Use SAME_INODE instead of reinventing it.

	maint: test that cmpbuf.h is self-contained
	* lib/cmpbuf.c: Include cmpbuf.h before all files but config.h.

	maint: rely on Gnulib SSIZE_MAX
	* lib/cmpbuf.c (SSIZE_MAX): Remove, as Gnulib now supplies it.

	maint: coalesce duplicate MIN, MAX
	* bootstrap.conf (gnulib_modules): Add minmax.
	* lib/cmpbuf.c, src/system.h: Include minmax.h.
	(MIN, MAX): Remove.

	maint: depend directly on intprops
	* bootstrap.conf (gnulib_modules): Add intprops, since
	we are including intprops.h.

	build: update gnulib submodule to latest

2023-05-30  Paul Eggert  <eggert@cs.ucla.edu>

	maint: even safer word type
	* src/system.h (word): Change from ‘void *’ to ‘struct incomplete *’
	since that’s even less likely to be misused.

	maint: omit ‘register’
	The ‘register’ keyword is no longer needed for optimization.
	With GCC 13.1 x86-64 compiled with -O2, omitting ‘register’ did not
	change the generated code.

	diff: fix unlikely integer overflow
	* src/analyze.c (discard_confusing_lines):
	Avoid theoretical possibility of integer overflow.

2023-05-30  Paul Eggert  <eggert@cs.ucla.edu>

	maint: prefer ‘*const’ to ‘* const’
	Prefer declarations like ‘char *const *x;’ to ‘char * const *x;’,
	for consistency between ‘*const’ and ‘*x’, and to highlight the
	fact that the ‘const’ belongs to the preceding ‘*’ not to the
	following ‘*’.

	Similarly for ‘* volatile’.

2023-05-30  Paul Eggert  <eggert@cs.ucla.edu>

	scripts: sync git-hooks from coreutils

	maint: calculate log base 2 more efficiently
	* bootstrap.conf (gnulib_modules): Add count-leading-zeros.
	* src/analyze.c (discard_confusing_lines, diff_2_files):
	* src/io.c (read_files):
	Prefer floor_log2 to doing it by hand.
	* src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c:
	Define SYSTEM_INLINE, for system.h.
	* src/system.h: Include count-leading-zeros.h.
	(SYSTEM_INLINE): New macro.
	(LIN_MAX): Verify that it does not exceed IDX_MAX, so that
	floor_log2 is safe to use for lin values too.
	(floor_log2): New inline function.

	maint: use xpalloc
	* bootstrap.conf (gnulib_modules): Add ialloc, to document
	the now-direct dependency.
	* src/diff.c (add_regexp):
	* src/diff3.c (read_diff):
	* src/dir.c (dir_read):
	* src/io.c (slurp, find_and_hash_each_line, find_identical_ends):
	* src/sdiff.c (diffarg):
	Prefer xpalloc to doing it by hand.
	* src/io.c: Include ialloc.h, for irealloc.
	(equivs_alloc): Now idx_t, not lin, for xpalloc.
	(sip): Don’t bother subtracting 2 * sizeof (word) from the
	buffer_lcm upper bound, as later code works anyway now.
	(slurp): Simplify buffer allocation so that xpalloc can be used.
	Use irealloc for speculative reallocation, since the code could
	work anyway if the irealloc fails.  Use current->eof to check
	for EOF, rather than the less-intuitive buffer size checks.

	maint: prefer signed sizes for allocation
	* src/analyze.c (discard_confusing_lines, diff_2_files):
	* src/cmp.c (main):
	* src/diff.c (main, add_regexp):
	* src/diff3.c (read_diff):
	* src/dir.c (dir_read):
	* src/io.c (slurp, find_and_hash_each_line, find_identical_ends):
	* src/sdiff.c (lf_init, diffarg): Prefer ximalloc to xmalloc, etc.
	Also prefer letting the xmalloc.c functions multiply (with
	overflow checking) than doing it by hand (without).

	diff: prefer signed types in util.c
	* src/util.c (struct msg, message, struct bin_str)
	(get_funky_string, c_escape, lines_differ, output_1_line)
	(analyze_hunk):
	Prefer signed types to size_t.

	sdiff: prefer signed types
	* src/sdiff.c (ck_fread, ck_fwrite, expand_name, lf_refill)
	(lf_snarf, diffarg, edit):
	Prefer idx_t to size_t.

	diff: prefer signed types in io.c
	* src/io.c (struct equivclass, nbuckets)
	(find_and_hash_each_line, guess_lines, read_files):
	Prefer idx_t to size_t.

	diff: prefer signed types in ifdef.c
	* src/ifdef.c (do_printf_spec):
	Prefer idx_t to size_t.

	diff: prefer signed types in dir.c
	* src/dir.c (struct dirdata, dir_read):
	Prefer idx_t to size_t.

	diff: prefer signed types in diff.c
	* src/diff.c (struct regexp_list, option_list, main, add_regexp):
	Prefer idx_t to size_t.

	diff3: prefer signed types
	* src/diff3.c (struct diff_block, struct diff3_block)
	(copy_stringlist, create_diff3_block, compare_line_list)
	(read_diff, scan_diff_line, output_diff3, process_diff):
	Prefer idx_t to size_t.

	maint: use safer type for ‘word’
	* src/system.h (word): Change it from size_t to void *,
	so that uses aren’t tempted to treat it as an integer.

	diff: prefer signed types in diff.h
	* src/diff.h (struct file_data):
	Prefer idx_t to size_t.  All uses changed.

	diff: prefer signed types in context.c
	* src/context.c (find_function):
	Prefer idx_t to size_t.

	cmp: prefer signed types
	* src/cmp.c (buf_size, words_per_buffer, cmp, count_newlines):
	Prefer idx_t to size_t.

	diff: prefer signed types in analyze.c
	* src/analyze.c (discard_confusing_lines, diff_2_files):
	Prefer signed types to size_t.

	diff: use intmax_t for column widths
	Don’t represent column widths and tab stops as size_t, since they
	are not object sizes.  Instead, use intmax_t.  This is better than
	uintmax_t since gcc -fsanitize=undefined can catch overflows.
	* src/diff.c (main):
	* src/diff.h (tabsize, sdiff_half_width, sdiff_column2_offset):
	* src/io.c (find_and_hash_each_line):
	* src/side.c (tab_from_to, print_half_line, print_1sdiff_line):
	* src/util.c (lines_differ, output_1_line):
	Use intmax_t for column numbers, not size_t.
	* src/io.c (find_and_hash_each_line): Count only columns since the
	last tab stop, to avoid signed integer overflow.  (The old code
	had this possibility on odd but valid platforms where SIZE_MAX <=
	INT_MAX.)
	* src/util.c (lines_differ, output_1_line): Use a separate counter
	for tab stops, so that the column count counts only columns since
	the last tab stop.  This avoids integer overflow when tabsize is
	large.  (The old code mishandled this situation.)

	maint: update cmpbuf.c comment
	Update comment to refer to FreeBSD 13, which is current,
	instead of to Tru64 which is not.

	maint: check for unlikely st_blksize overflow
	Prefer idx_t to size_t in lib/cmpbuf.c and related buffer-size code.
	Because POSIX says blksize_t can be wider than idx_t,
	check for overflow when copying the former to the latter.
	* bootstrap.conf (gnulib_modules): Add idx.
	* lib/cmpbuf.c (block_read, buffer_lcm):
	Prefer idx_t to size_t.  All uses changed.
	* lib/cmpbuf.c (block_read): Return ptrdiff_t instead of size_t.
	All uses changed.
	(buffer_lcm): Help the compiler by checking for negative args,
	even though they are not allowed.
	* lib/cmpbuf.h: Include idx.h and stddef.h, for idx_t and ptrdiff_t,
	so that this include file is self-contained.
	* src/analyze.c (diff_2_files):
	* src/cmp.c (main):
	* src/diff.c, src/io.c: Do not include stdckdint.h here,
	since system.h now does that.
	* src/diff3.c (read_diff):
	* src/io.c (sip):
	Protect against negative STAT_BLOCKSIZE, or STAT_BLOCKSIZE
	outside idx_t range.
	* src/system.h: Include stdckdint.h, idx.h.

2023-05-24  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2023-05-22  Paul Eggert  <eggert@cs.ucla.edu>

	maint: C99 for cmpbuf.c
	* lib/cmpbuf.c (buffer_lcm):
	Put decls closer to uses.

	diff: C99 style for util.c
	* src/util.c (get_funky_string, parse_diff_color, begin_output)
	(finish_output, lines_differ, print_script, output_1_line)
	(analyze_hunk):
	Put decls closer to uses.

	diff: C99 style for side.c
	* src/side.c (tab_from_to, print_sdiff_hunk):
	Put decls closer to uses.

	diff: C99 style for sdiff.c
	* src/sdiff.c (usage, main, trapsigs, untrapsig, flush_line)
	(edit, interact):
	Put decls closer to uses.

	diff: C99 style for normal.c
	* src/normal.c (print_normal_hunk):
	Put decls closer to uses.

	diff: C99 style for io.c
	* src/io.c (sip, slurp, find_and_hash_each_line)
	(find_identical_ends, read_files):
	Put decls closer to uses.

	diff: C99 decl style in ifdef.c
	* src/ifdef.c (format_ifdef, format_group, print_ifdef_lines)
	(do_printf_spec, scan_char_literal):
	Put decls closer to uses.

	diff: C99 decl style in ed.c
	* src/ed.c (print_ed_hunk, pr_forward_ed_hunk, print_rcs_hunk):
	Put decls closer to uses.

	diff: C99 decl style in dir.c
	* src/dir.c (dir_read, diff_dirs, find_dir_file_pathname):
	Put decls closer to uses.

	diff: C99 decl style in diff.c
	* src/diff.c (option_list, main, usage, compare_files):
	Put decls closer to uses.

	diff3: C99 decl style
	* src/diff3.c (main, usage, make_3way_diff)
	(using_to_diff3_block, create_diff3_block, process_diff)
	(process_diff_control, read_diff, output_diff3, dotlines)
	(output_diff3_edscript, output_diff3_merge)
	(reverse_diff3_blocklist):
	Put decls closer to uses.

	diff: C99 decl style in context.c
	* src/context.c (print_context_script, pr_context_hunk)
	(pr_unidiff_hunk, mark_ignorable):
	Put decls closer to uses.

	cmp: C99 decl style in cmp.c
	* src/cmp.c (usage, main, cmp, count_newlines):
	Put decls closer to uses.

	diff: C99 decl style in analyze.c
	* src/analyze.c (discard_confusing_lines, shift_boundaries)
	(diff_2_files): Assume C99 decls after statements.

	sdiff: remove an IF_LINT
	* src/sdiff.c (edit): Remove an IF_LINT, which no longer seems
	to be needed with current GCC.

	sdiff: prefer functions to macros
	* src/sdiff.c (sighandler): New type.
	(signal_handler) [!HAVE_SIGACTION]:
	(initial_handler): Now static functions, not macros.

	diff: prefer functions in io.c
	* src/io.c (HASH_VALUE_WIDTH): New constant.
	(rol, hash): New static functions, replacing ...
	(ROL, HASH): ... these macros.  All uses changed.

	diff: prefer function to DIR_P macro
	* src/diff.c (dir_p): New static function, replacing ...
	(DIR_P): ... this macro.  All uses changed.

2023-05-21  Jim Meyering  <meyering@fb.com>

	maint: prefer ckd_add, ckd_mul to INT_ADD_WRAPV, INT_MULTIPLY_WRAPV
	* bootstrap.conf (gnulib_modules): Add stdckdint.
	* lib/cmpbuf.c: Use ckd_mul rather than INT_MULTIPLY_WRAPV.
	Include stdckdint.h, not "intprops.h".
	* src/diff.c: Similar, but for both ckd_add and ckd_mul.
	* src/io.c: Likewise for ckd_add.

2023-05-21  Jim Meyering  <meyering@meta.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.10
	* NEWS: Record release date.

2023-05-21  Jim Meyering  <meyering@fb.com>

	build: skip the sole perl-requiring test when there is no usable perl
	* tests/init.cfg (require_perl_): New function, from coreutils.
	* tests/large-subopt: Use it.
	Reported by Bruno Haible in
	https://lists.gnu.org/r/diffutils-devel/2023-05/msg00003.html

2023-05-20  Jim Meyering  <meyering@fb.com>

	build: fix a new syntax-check failure
	* src/diff.h (robust_output_style): Put DIFF_INLINE and
	the function name on the same line, so that syntax-check's
	naive parsing can spot this function.
	* cfg.mk (_gl_TS_extern): Add DIFF_INLINE.

	build: modernize bootstrap prerequsite tools
	Following Pádraig Brady's example from coreutils, ...
	* bootstrap.conf: Add an explicit requirement on m4.
	Add an explicit requirement on texi2pdf which is often packaged
	separately to makeinfo and induces a failure far down the
	distribution phase if not present.
	Replace the rsync dependency with wget,
	which gnulib changed to in 2018.
	Also, add an xz requirement and a version for autopoint.

2023-05-19  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest
	* src/analyze.c (OFFSET_MAX): New macro, needed for
	latest gnulib.

	diff: avoid a macro in diff.h
	* src/diff.h (FILE_BUFFER): Remove.
	* src/io.c (file_buffer): New static function.  All uses of
	FILE_BUFFER replaced.

	sdiff: avoid some macros in sdiff.c
	* src/sdiff.c (PROGRAM_NAME, SDIFF_BUFSIZE):
	Now constants, not macros.

	diff3: avoid macros in diff3.c
	* src/diff3.c (PROGRAM_NAME, FILE0, FILE1, FILE2, FILE3, FO, FC)
	(RANGE_START, RANGE_END): Now constants, not macros.

	cmp: avoid macros in cmp.c
	* src/cmp.c (PROGRAM_NAME): Now a constant, not a macro.
	(hard_locale_LC_MESSAGES): Now a function, not a macro.
	All uses changed.

	diff: avoid macros in diff.c
	* src/diff.c (PROGRAM_NAME, NONEXISTENT, UNOPENED):
	Now constants, not macros.
	(errno_encode, errno_decode): Now functions, rather than
	macros ERRNO_ENCODE and ERRNO_DECODE.  All uses changed.

	diff: use function for robust_output_style
	* bootstrap.conf (gnulib_modules): Add extern-inline.
	* src/diff.h: Use _GL_INLINE_HEADER_BEGIN and _GL_INLINE_HEADER_END.
	(DIFF_INLINE): New macro.
	(robust_output_style): Now an inline function, not a macro
	ROBUST_OUTPUT_STYLE.  All uses changed.

	cmp: don’t give up if fstat fails
	* src/cmp.c (main, cmp): If fstat fails, simply record the failure
	and move on, instead of exiting.  Modify other uses of the struct
	stat to do something reasonable if the status is missing.

	diff3: don’t give up if fstat fails
	* src/diff3.c (read_diff): Work even if fstat fails,
	e.g., due to EOVERFLOW.

	diff3: fix race condition involving directories
	This fixes a TOC-TOU race with "diff3 A B C" when one
	of its arguments is a directory.
	* src/diff.c (no_directory): New static var.
	(NO_DIRECTORY_OPTION): New constant.
	(longopts): Add ---no-directory.
	(main): Support it.
	(compare_files): If ---no-directory is given, do not treat
	directories specially.
	* src/diff3.c (main): Do not check whether an argument is
	a directory.
	(read_diff): Pass ---no-directory to diff, so that it checks.

2023-05-13  Jim Meyering  <meyering@fb.com>

	maint: suppress new test's doubled-word syntax-check failure
	* cfg.mk (exclude_file_name_regexp--sc_prohibit_doubled_word):
	Exempt the new test's use of "in in".

2023-05-13  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2023-05-13  Carlo Marcelo Arenas Belón  <carenas@gmail.com>  (tiny change)

	gnulib: fix Y2038 bug (again)
	AC_SYS_LARGEFILE meaning has changed, need AC_SYS_YEAR2038 as well

	* NEWS: mention this
	* tests: add test
	* bootstrap.conf: add year2038

2023-02-24  Paul Eggert  <eggert@cs.ucla.edu>

	maint: add 'diff --git' TODO
	* TODO: Suggest better compatibility with 'git diff -p'.
	From a suggestion by Linus Torvalds
	<https://lkml.org/lkml/2023/2/24/797>.

2023-02-10  Paul Eggert  <eggert@cs.ucla.edu>

	maint: update .gitignore
	.gitignore: Update for some recent changes, and simplify.

	diff: fix bug where -D does not work
	Problem reported by Robert Webb (bug#61193).
	* NEWS: Mention this.
	* src/diff.c (main): Omit stray ‘sizeof’.
	* tests/ifdef: New test.
	* tests/Makefile.am (TESTS): Add it.

2023-02-07  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2023-02-05  Paul Eggert  <eggert@cs.ucla.edu>

	diff: use C23 bool
	* bootstrap.conf (gnulib_modules): Add stdbool.
	* src/die.h, src/system.h: Do not include <stdbool.h>.

	diff: prefer nullptr to NULL
	* bootstrap.conf (gnulib_modules): Add c-nullptr.
	* src/cmp.c (main):
	* src/context.c (pr_context_hunk, pr_unidiff_hunk)
	(mark_ignorable, find_function):
	* src/diff.c (longopts, main, specify_value, specify_style)
	(specify_colors_style, compare_files):
	* src/diff3.c (main, process_diff):
	* src/dir.c (find_dir_file_pathname):
	* src/ifdef.c (scan_char_literal):
	* src/sdiff.c (main):
	* src/util.c (process_signals, install_signal_handlers)
	(color_ext_list, color_indicator, indicator_name)
	(parse_diff_color):
	Prefer C23-style nullptr to NULL, as nullptr is a bit better.

	doc: update README-hacking
	* README-hacking: Update for current bootstrap.

	maint: sync bootstrap from Gnulib
	bootstrap: sync from Gnulib

	build: update gnulib submodule to latest
	* lib/sh-quote.c.diff: Remove, as Gnulib now has this.

	build: add libraries
	* src/Makefile.am (LDADD, sdiff_LDADD): Add Gnulib libraries that
	in theory would be needed on unusual platforms.  In practice,
	these are typicall empty or are duplicates of other library
	arguments and so are redundant.

2023-02-04  Jim Meyering  <meyering@fb.com>

	doc: update HACKING
	* HACKING: Update from grep's HACKING.

2023-02-04  Jim Meyering  <meyering@meta.com>

	maint: prefer https: to git:
	The idea is to defend against some adversary-in-the-middle attacks.
	Also prefer git.savannah.gnu.org over its shorter alias, git.sv.gnu.org
	to avoid a warning e.g., from git clone.
	Also, drop any final ".git" suffix on the resulting URIs.
	Inspired by Paul Eggert's nearly identical changes to coreutils.

2023-01-16  Jim Meyering  <meyering@fb.com>

	tests: accommodate newer GNU make's SIGPIPE-ignore
	* tests/colors: Allow an exit code of not just 141 (SIGPIPE),
	but also "error": 2.
	Reported by Tomasz Kłoczko in http://bugs.gnu.org/59905.

2023-01-15  Jim Meyering  <meyering@meta.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.9
	* NEWS: Record release date.

	build: update gnulib to latest

2023-01-05  Jim Meyering  <meyering@fb.com>

	tests: avoid large-subopt XPASS on systems without perl
	* tests/large-subopt: Use $PERL, rather than hard-coding "perl".
	* bootstrap.conf (gnulib_modules): Add "perl" to the list.
	Reported by Bruno Haible in
	https://lists.gnu.org/r/diffutils-devel/2023-01/msg00000.html

2023-01-05  Bruno Haible  <bruno@clisp.org>

	tests: avoid a test failure when using Solaris 11.4's old grep
	* tests/colors (nanosecond_zeros): Use a dumbed-down grep '\.'
	in place of "grep -F ." to accommodate Solaris 11.4's old versions
	of grep in the default PATH. Reported here:
	https://lists.gnu.org/r/diffutils-devel/2023-01/msg00001.html

2023-01-01  Jim Meyering  <meyering@fb.com>

	build: update gnulib to latest

	maint: update copyright dates

2022-12-31  Paul Eggert  <eggert@cs.ucla.edu>

	build: simplify GCC 12 false alarm workaround
	* src/util.c (print_message_queue): Pacify GCC in a
	more-straightforward way.

	maint: fix assumption typo
	Fix a typo I introduced in my August 2021 signal handling fixes.
	Problem reported by Sam James (Bug#60457).
	* src/util.c (xsigismember): Don’t assume sigismember cannot return 0.

2022-12-30  Jim Meyering  <meyering@fb.com>

	build: update gnulib to latest

	build: temp?-disable -Wanalyzer-use-of-uninitialized-value
	* src/util.c (print_message_queue): This function triggers false
	positive warnings from GCC12, so add pragmas to ignore that new warning
	in this one function. Required when using either of these:
	- gcc version 12.2.1 20221121
	- gcc version 13.0.0 20221229 (experimental)

2022-12-11  Jim Meyering  <meyering@fb.com>

	build: update gnulib to latest

2022-11-12  Jim Meyering  <meyering@fb.com>

	build: update gnulib to latest

2022-02-14  Paul Eggert  <eggert@cs.ucla.edu>

	doc: mark up SEE ALSO (Bug#53976)

2022-01-24  Jim Meyering  <meyering@fb.com>

	tests: fix false-failure on systems without valgrind
	* tests/init.cfg (require_valgrind_): Use exit status of subshell,
	not that of the "local" declaration.

2022-01-14  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2022-01-03  Jim Meyering  <meyering@fb.com>

	maint: avoid new syntax-check failure
	* cfg.mk (local-checks-to-skip): Add sc_indent, to skip it.
	Otherwise, "make syntax-check" would fail.

	maint: make update-copyright

	build: update gnulib to latest; also bootstrap and init.sh

2021-10-30  Paul Eggert  <eggert@cs.ucla.edu>

	maint: modernize README-{hacking,prereq}

2021-10-16  Paul Eggert  <eggert@cs.ucla.edu>

	doc: copy fdl.texi into git
	This pacifies this notice from ./bootstrap: “Notice from module
	fdl: Don't use this module! Instead, copy the referenced license
	file into your version control repository.”
	* bootstrap.conf (gnulib_modules): Remove fdl.
	* doc/fdl.texi: New file, taken from Gnulib.

	maint: direct dependency on time_rz now
	Now that diff calls tzalloc, it depends directly on time_rz.
	* bootstrap.conf (gnulib_modules): Add time_rz.

	build: update gnulib submodule to latest

2021-10-15  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix timezone bug on Solaris
	Problem reported by Vladimir Marek (bug#51228).
	* NEWS: Mention this.
	* src/context.c (print_context_label): Pass localtz to nstrftime,
	instead of always passing 0.
	* src/diff.c (main) [!HAVE_TM_GMTOFF]:
	Initialize localtz if time_format uses %z.
	* src/diff.h (localtz): New decl.
	* tests/Makefile.am (TESTS): Add timezone.
	* tests/timezone: New test.

2021-08-31  Paul Eggert  <eggert@cs.ucla.edu>

	diff3: port better to MS-Windows
	* src/diff3.c (enum diff_type): Prefix constants like ADD with
	"DIFF_" to avoid collisions with unwise system headers.

2021-08-30  Paul Eggert  <eggert@cs.ucla.edu>

	maint: port better to non-POSIX
	Problem privately reported by Gisle Vanem for MS-Windows.
	* src/util.c (sig, install_signal_handlers):
	Don’t assume SIGTSTP, SIGALRM, SIGQUIT.
	(is_tstp_index): New function, for use in SIGTSTP avoidance.

	maint: prefer attribute.h attributes
	Prefer the macros used in attribute.h, and _Noreturn,
	to the by-hand use of __attribute__, as this is more portable.
	* bootstrap.conf (gnulib_modules): Add attribute.
	* src/system.h: Include attribute.h.  All uses of
	attributes changed to use the attribute.h macros.
	Plus, use _Noreturn.
	(FALLTHROUGH): Remove; attribute.h now defines this.

	build: update gnulib submodule to latest

	diff: avoid double translation
	* src/analyze.c (briefly_report): Do not translate here,
	as ‘message’ translates its format.

	diff: use variable arg list for messages
	This simplifies the code by using varargs.
	* bootstrap.conf (gnulib_modules): Add flexmember.
	(XGETTEXT_OPTIONS): Do not flag message5.
	* src/util.c: Include flexmember.h, stdarg.h.
	(struct msg): New members msgid, argbytes.  args is now
	FLEXIBLE_ARRAY_MEMBER, and does not contain msgid.
	All uses changed.
	(message): Now varargs.  Detect number of args by counting '%'s.
	Use FLEXSIZEOF, to avoid problems on systems with buggy
	allocators.  Avoid redundant ‘*p = 0’ when *p is already zero
	after stpcpy.
	(message5): Remove; all callers changed to use ‘message’.
	(print_message_queue): Abort if too many args were passed;
	this cannot happen with current diffutils.

2021-08-29  Paul Eggert  <eggert@cs.ucla.edu>

	diff: port better to MS-Windows
	Problem reported by Gisle Vanem (Bug#36488#30).
	* src/util.c (xsigaction) [SA_NOCLDSTOP]: Remove; no longer needed.
	(install_signal_handlers): If the first call to sigaction or
	signal fails, do not exit; just skip the signal and continue,
	in case the runtime does not support the signal even though the
	corresponding SIG* macro is defined.

2021-08-28  Paul Eggert  <eggert@cs.ucla.edu>

	diff: cleanup signal handling just before exit
	This should fix an unlikely signal handling bug with colored
	output, and should also fix a Debian FTBFS (Fails To Build From
	Source) on powerpc64le-linux.  See Bug#34519 and Frédéric
	Bonnard’s report in:
	https://bugs.debian.org/922552#19
	* bootstrap.conf (gnulib_modules): Add raise, sigprocmask.
	* src/diff.c (main): Call cleanup_signal_handlers before exiting.
	Don’t bother calling ‘exit’; no longer needed nowadays.
	* src/util.c (sigprocmask, siginterrupt) [!SA_NOCLDSTOP]:
	Define to 0 instead of empty, since the results are now used.
	(sigset_t) [!SA_NOCLDSTOP]: Remove; we now rely on Gnulib.
	(xsigaction) [SA_NOCLDSTOP]: New function.
	(xsigaddset, xsigismember, xsignal, xsigprocmask): New functions.
	(some_signals_caught): New static var.
	(process_signals): Omit a conditional branch.
	Don’t bother loading interrupt_signal if stop_signal_count is nonzero.
	(process_signals, install_signal_handlers):
	Check for failures from sigprocmask etc.
	(sig, nsig): Now at top level, since multiple functions need them.
	(install_signal_handlers): No need for caught_sig array;
	just use caught_signals.  However, set some_signals_caught.
	(cleanup_signal_handlers): New function.

2021-08-22  Paul Eggert  <eggert@cs.ucla.edu>

	diff: add integer overflow checking
	* src/diff.c (option_list, main): Check for integer overflow
	in some unlikely and hard-to-test cases.

	maint: refactor integer overflow checking
	Rely on more-modern Gnulib capabilities instead of doing
	integer overflow checking by hand, in some cases.
	* lib/cmpbuf.c (buffer_lcm):
	* src/io.c (slurp, find_identical_ends):
	Use INT_ADD_WRAPV and INT_MULTIPLY_WRAPV rather than checking
	overflow by hand.
	* src/diff3.c (process_diff):
	* src/dir.c (dir_read):
	* src/io.c (find_identical_ends, read_files):
	Use xnmalloc rather than checking overflow by hand.
	(read_files): Rely on xcalloc to do overflow checking.

	diff: avoid sprintf %s
	sprintf fails if the result contains more than INT_MAX bytes,
	so rework the code to avoid usage of sprintf %s where the
	string might be longer than that.
	* bootstrap.conf (gnulib_modules): Remove xvasprintf.
	* src/diff.c (specify_style):
	* src/util.c (begin_output):
	Rewrite to avoid sprintf %s.
	* src/util.c: Do not include xvasprintf.h.
	(concat): Remove, as it uses sprintf %s.  All uses rewritten.

	diff: use mempcpy
	* bootstrap.conf (gnulib_modules): Add mempcpy, stpcpy.
	* src/ifdef.c (do_printf_spec):
	* src/sdiff.c (expand_name, lf_snarf, temporary_file):
	* src/util.c (message5):
	Prefer mempcpy to memcpy plus manual size-updating.
	Prefer stpcpy to mempcpy plus manual size-spec.

	sdiff: fix unlikely memory leak
	* src/sdiff.c (temporary_file): Fix memory leak when mkstemp fails.
	Don’t assume temporary file name length fits in ‘int’.

	diff3: simplify process_diff
	* src/diff3.c (process_diff): Remove LAST_BLOCK arg, since callers
	no longer needed it.  All callers changed.  This removes an
	unnecessary initialization of bptr to NULL.

	maint: modernize IF_LINT for GCC 11.2.1
	* src/cmp.c (cmp):
	* src/dir.c (find_dir_file_pathname):
	* src/sdiff.c (edit):
	Mention which GCC bug this IF_LINT works around.
	* src/diff3.c (process_diff):
	Always initialize to NULL, to avoid problems on mostly-theoretical
	hosts where accessing uninitialized variables traps.  The next
	patch will have a better fix for this.
	* src/ifdef.c (do_printf_spec):
	No need for IF_LINT in GCC 11.2.1.

	maint: lint → GCC_LINT
	‘lint’ is for traditional lint and perhaps some other tools;
	‘GCC_LINT’ is targeted more for what we do.
	Gnulib accepts either, but we might as well be more accurate.
	* configure.ac (GCC_LINT): Define this instead of ‘lint’.
	All uses changed.

	diff: remove printint
	* src/system.h (printint): Remove.  All uses removed.  This type
	was only for porting to pre-C89 hosts, and is no longer needed.

	diff: remove INT_MAX limit on -F/-p searches
	* src/context.c (find_function): Don’t limit function-line
	searches to INT_MAX bytes, removing a FIXME.

	maint: .gitignore updates
	* .gitignore: Remove lib/unused-parameter.h.  Add all of m4, since
	no files there need to be committed; this lets us remove
	m4/.gitignore and m4/gnulib-cache.m4.  Add *.orig, *.patch, .Tpo,
	/*.diff, lib/*/ (which lets us remove /lib/sys/), lib/ctype.h,
	lib/errno.h, lib/float.h, lib/fnmatch.h, lib/getopt-cdefs.h,
	lib/getopt.h, lib/limits.h, lib/sigsegv.h, lib/stdalign.h,
	lib/stdarg.h, lib/stdbool.h, lib/stddef.h, lib/stdint.h,
	lib/stdopen.[ch], vc-dwim-log-*.  Add slashes to autom4te.cache,
	build-aux.  Remove redundant initial slashes from patterns that
	also have internal slashes.  Remove plain ABOUT-NLS, since
	/ABOUT-NLS suffices.  Sort using LC_ALL=C.

	maint: omit unused function if not debugging
	* src/util.c (debug_script): Compile only if DEBUG.

	maint: remove prepargs
	* lib/Makefile.am (noinst_HEADERS): Remove prepargs.h.
	(libdiffutils_a_SOURCES): Remove prepargs.c.
	* lib/prepargs.c, lib/prepargs.h: Remove.  Hasn’t been
	needed for many years.
	* src/diff.c: Do not include prepargs.h.

	maint: zalloc → xzalloc
	* src/util.c (zalloc): Remove.  All uses replaced
	by xzalloc, which means the same thing.

2021-08-22  Paul Eggert  <eggert@cs.ucla.edu>

	diff3: suppress -fanalyzer alarms
	* src/diff3.c: Add pragma to suppress -Wanalyzer-null-dereference
	alarms.

	* src/diff.h (find_dir_file_pathname): Add malloc-related
	attributes, to pacify gcc -Wsuggest-attribute=malloc.

2021-08-22  Paul Eggert  <eggert@cs.ucla.edu>

	maint: remove January workaround for Gnulib issue
	* configure.ac: Don’t add -Wno-analyzer-null-argument, since
	the issue is now fixed in Gnulib.

	build: update gnulib submodule to latest

2021-08-01  Paul Eggert  <eggert@cs.ucla.edu>

	maint: remove stray init.cfg
	* init.cfg: Remove.  I guess this file was a stray, since it was a
	copy of tests/init.cfg when it was checked in, and it hasn’t been
	maintained since.

	tests: port to valgrind 3.16.0 + GCC 11.2
	* tests/init.cfg (stderr_fileno_): Reject valgrind if it reports a
	"Serious error" on a trival use of ‘diff’.  Without this patch, on
	RHEL 8.4 when I compile diffutils with a GCC 11.2.0 that I built
	myself, ‘valgrind diff’ spits out messages like WARNING: Serious
	error when reading debug info / When reading debug info from diff:
	Ignoring non-Dwarf2/3/4 block in .debug_info’ and this causes the
	strip-trailing-cr test to fail.  I guess valgrind complains
	because the valgrind version 3.16.0 that came with RHEL 8.4 cannot
	grok the debug entries generated by GCC 11.2.0.

2021-08-01  Jim Meyering  <meyering@fb.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.8
	* NEWS: Record release date.

	build: update gnulib to latest

2021-07-31  Jim Meyering  <meyering@fb.com>

	cmp: avoid reading uninitialized memory
	[This *is* useful, so reapply. ]
	When comparing buffers a word at a time, cmp could read up to
	sizeof (word) - 1 uninitialized bytes.
	* src/cmp.c (cmp): Set not just a single guaranteed-differing
	sentinel byte just beyond any final read byte, but also ensure
	that any following bytes are defined, if those may be read via
	block_compare's word-at-a-time comparison.  Reported by Bruno Haible
	in https://lists.gnu.org/r/diffutils-devel/2021-07/msg00003.html

2021-07-28  Bruno Haible  <bruno@clisp.org>

	cmp: avoid reading uninitialized memory
	One or both of the sentinel bytes were copies of uninitialized values.
	* src/cmp.c (cmp): Use arbitrary initialized values for the
	sentinel bytes.

2021-07-28  Jim Meyering  <meyering@fb.com>

	cmp: revert preceding change
	It did not solve the problem. The next patch does.

2021-07-27  Jim Meyering  <meyering@fb.com>

	cmp: avoid reading uninitialized memory
	When comparing buffers a word at a time, cmp could read up to
	sizeof (word) - 1 uninitialized bytes.
	* src/cmp.c (cmp): Set not just a single guaranteed-differing
	sentinel byte just beyond any final read byte, but also ensure
	that any following bytes are defined, if those may be read via
	block_compare's word-at-a-time comparison.  Reported by Bruno Haible
	in https://lists.gnu.org/r/diffutils-devel/2021-07/msg00003.html

2021-07-19  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2021-05-21  Paul Eggert  <eggert@cs.ucla.edu>

	diff: better --color help
	* src/diff.c (option_help_msgid): Reword --color help without
	using the confusing word “default”.  Problem reported
	by Peter Oliver (Bug#48532).

2021-05-20  Paul Eggert  <eggert@cs.ucla.edu>

	doc: fix URL in HACKING

2021-03-24  Paul Eggert  <eggert@cs.ucla.edu>

	diff: pacify compiler re style
	* src/diff.c (usage): Prefer &"string"[N] to "string" + N.
	Some compilers complain about the latter, as they worry C++
	refugees will think it’s string concatnation.

	diff3: avoid signed int overflow
	* src/diff3.c (main): Avoid signed integer overflow in the very
	unlikely case of more than INT_MAX incompatible options.  Instead,
	use one bit to record the presence of each type of incompatible
	option, and report an error if more than one bit is set.

	maint: don’t bother with -Wno-return-local-addr
	* configure.ac (WERROR_CFLAGS): Don’t bother with
	-Wno-return-local-addr as it doesn’t seem to work.
	Anyway, it’s no longer needed on Ubuntu 20.10.

	maint: disable -Wstack-protector
	* configure.ac (WERROR_CFLAGS): Disable -Wstack-protector, as it
	has a false alarm with lib/vasnprintf.c on Ubuntu 20.10 and it’s
	not worth working around.  Coreutils already disables it.

	diff: plug memory leak in ifdef.c
	Problem reported by Than (Bug#47362).
	Fix the bug by using xmalloca instead of vararrays.
	* bootstrap.conf (gnulib_modules): Add xmalloca; remove vararrays.
	* configure.ac: Remove AC_C_VARARRAYS.
	* src/ifdef.c: Include xmalloca.h instead of xalloc.h.
	(do_printf_spec): Use xmalloca instead of an xmalloc
	that lacks a corresponding ‘free’ if HAVE_C_VARARRAYS
	due to a typo in 2017-05-18T05:51:31Z!meyering@fb.com.

	build: update gnulib submodule to latest

2021-01-02  Paul Eggert  <eggert@cs.ucla.edu>

	maint: work around GCC -Wreturn-local-addr bug
	* configure.ac: Do not use -Wreturn-local-addr in Gnulib,
	to suppress a false alarm in vasnprintf.c.

2021-01-01  Jim Meyering  <meyering@fb.com>

	maint: update all copyright year number ranges
	Run "make update-copyright" and then...
	* gnulib: Update to latest with copyright year adjusted.
	* tests/init.sh: Sync with gnulib to pick up copyright year.
	* bootstrap: Likewise.

2020-12-05  Jim Meyering  <meyering@fb.com>

	build: require autoconf-2.64
	* configure.ac: Require 2.64, up from 2.63, to align with gnulib.

2020-03-15  Jim Meyering  <meyering@fb.com>

	build: update gnulib to latest

	doc: adjust formatting to make apropos (man -k) work better
	* man/Makefile.am $(dist_man1_MANS): Adjust sed substitution
	to also remove the space after "GNU". This avoids the single
	leading space on each man page title line.  I'm guessing that
	interfered with indexing/searching, causing "man -k diff3" to
	print this: diff3 (1) - (unknown subject).
	Reported by Dan Jacobon in http://bugs.gnu.org/39769.

2020-01-19  Jim Meyering  <meyering@fb.com>

	doc: correct an ancient "At present"
	* doc/diffutils.texi (Unified Format): Correct the now
	seriously outdated "At present" (referring to early 1990s)
	statement to be more of a historical note.
	Reported by Roland Illig in http://bugs.gnu.org/39184.

2020-01-05  Jim Meyering  <meyering@fb.com>

	doc: use program name, not "GNU", in the nroff/man header
	* man/Makefile.am (dist_man1_MANS): Elide "GNU " prefix
	from the generated prog+one-line-summary, so that help2man
	uses the program name rather than "GNU" as the nroff "name".
	Reported by Dan Jacobson in http://bugs.gnu.org/38574.

2020-01-01  Jim Meyering  <meyering@fb.com>

	maint: update all copyright year number ranges
	Run "make update-copyright" and then...
	* gnulib: Update to latest with copyright year adjusted.
	* tests/init.sh: Sync with gnulib to pick up copyright year.
	* bootstrap: Likewise.

2019-12-29  Jim Meyering  <meyering@fb.com>

	maint: avoid gnulib-tool deprecation warnings, and build failure
	* bootstrap.conf (gnulib_modules): Use getopt-gnu, rather than
	obsolete "getopt" module. Use nstrftime in place of strftime.
	(avoided_gnulib_modules): Do not avoid the "lock" module. That
	would lead to a build failure due to "glthread/lock.h not found".

	maint: avoid syntax-check failure
	* po/POTFILES.in: Add argmatch.h; remove xstrtol-error.c

	maint: disable two and reenable many warning options
	* configure.ac (GNULIB_WARN_CFLAGS): Disable -Wduplicated-branches
	and -Wreturn-local-addr, due to a couple of false-positive warnings.
	(WARN_CFLAGS): Reenable many warnings that now (with recent gcc)
	provoke no false positive.

	maint: avoid gnulib's lock-tests module
	* bootstrap.conf (avoided_gnulib_modules): Also --avoid=lock-tests
	to avoid gnulib-related build failure.

2019-12-23  Jim Meyering  <meyering@fb.com>

	build: update gnulib to latest
	* gnulib: Update submodule to latest.
	* bootstrap: Copy from gnulib.
	* tests/init.sh: Likewise.

2019-12-20  Jim Meyering  <meyering@fb.com>

	maint: tweak bootstrap.conf
	* bootstrap.conf (buildreq): Require at least autoconf 2.62,
	up from 2.61, just as grep and coreutils do.
	(bootstrap_post_import_hook): "Copy pkg-config's pkg.m4 ...",
	copied from grep's bootstrap.conf.
	(avoided_gnulib_modules): Pull this definition to the top.
	Formatting.

2019-10-01  Dave Odell  <dmo2118@gmail.com>  (tiny change)

	cmp: add test case for Bug#37558
	* tests/cmp: New test case (Bug#37558).

2019-10-01  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: fix -l width bug
	Problem reported by Dave Odell (Bug#37558).
	* src/cmp.c (cmp): Treat negative ‘bytes’ as infinite, fixing a
	bug introduced in the 2019-08-27 patch that fixed Bug#35256.

2019-08-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: don’t mistreat -N in arg as a large number
	Problem reported by alec (Bug#35256).
	* NEWS: Mention the fix.
	* bootstrap.conf (gnulib_modules): Use strtoimax and xstrtoimax,
	not strtoumax and strtoumax.
	* src/cmp.c (bytes): Now signed, with -1 representing no limit.
	All uses changed.
	* src/cmp.c (specify_ignore_initial, main):
	* src/diff.c (main):
	* src/ifdef.c (format_group):
	* src/sdiff.c (interact):
	Use strtoimax, not strtoumax.

	build: update gnulib submodule to latest

2019-07-19  Paul Eggert  <eggert@cs.ucla.edu>

	maint: ignore ‘configure’ temporaries
	* .gitignore: Ignore confdefs*, conftest*.

	maint: avoid Gnulib setlocale module
	Problem reported for MS-Windows by Richard Gering (Bug#34376).
	Diffutils doesn’t need any of the Gnulib fixes for setlocale.
	* bootstrap.conf (gnulib_tool_option_extras):
	Avoid the setlocale module.

2019-05-24  KO Myung-Hun  <komh@chollian.net>

	tests: init.cfg: use $PATH_SEPARATOR not ':'
	On OS/2, a path separator is semi-colon ';' not colon ':'.
	* tests/init.cfg: Replace ':' with $PATH_SEPARATOR.

2019-01-20  Jim Meyering  <meyering@fb.com>

	build: ensure no VLA is used
	Cause developer builds to fail for any use of a VLA.
	VLAs (variable length arrays) limit portability.
	* configure.ac (nw): Remove -Wvla from the list of disabled warnings,
	thus enabling the warning when configured with --enable-gcc-warnings.
	(GNULIB_NO_VLA) Define, disabling use of VLAs in gnulib.  This commit
	is functionally equivalent to coreutils' v8.30-44-gd26dece5d.

	build: update gnulib to latest
	* gnulib: Update to latest.
	* po/POTFILES.in: Add lib/xstdopen.c.

2019-01-06  Paul Eggert  <eggert@cs.ucla.edu>

	diff: use xstdopen, not stdopen
	* bootstrap.conf (gnulib_modules):
	* src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c (main):
	Use xstdopen, not stdopen.

	build: update gnulib submodule to latest

2019-01-05  Jim Meyering  <meyering@fb.com>

	maint: convert all TABs to equivalent spaces in indentation
	Using this file,

	cat > leading-blank.exempt <<\EOF
	(\.gitmodules|help2man|pre-commit)$
	(?:^|\/)ChangeLog[^/]*$
	(?:^|\/)(?:GNU)?[Mm]akefile[^/]*$
	\.(?:am|mk)$
	EOF

	run the following command to convert all non-conforming leading white
	space to be all spaces:

	git ls-files \
	  | pcregrep -vf leading-blank.exempt \
	  | xargs pcregrep -l '^ *\t' \
	  | xargs perl -MText::Tabs -ni -le \
	    '$m=/^( *\t[ \t]*)(.*)/; print $m ? expand($1) . $2 : $_'

	Since that changed old NEWS, I also ran "make update-NEWS-hash"
	to update the old_NEWS_hash value in cfg.mk.

2019-01-05  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix cmp, diff3, sdiff with stdin closed
	* NEWS: Mention this.
	* src/cmp.c, src/diff3.c, src/sdiff.c: Include stdopen.h.
	(main): Call stdopen early.
	* src/cmp.c (main): Simplify now that we need not worry about
	stdin being closed.
	* src/diff.c (main): Translate stdopen diagnostic.

	diff: remove unportable ‘diff -N - f <&-’ feature
	* NEWS: Mention this.
	* bootstrap.conf (gnulib_modules): Add stdopen.
	* doc/diffutils.texi (Comparing Directories):
	Do not document behavior if stdin is closed.
	* src/diff.c: Include stdopen.h.
	(main): Call stdopen early.
	(compare_files) [__hpux]: Remove recently-introduced
	special case for HP-UX exec with stdin closed.
	* tests/new-file: Remove tests of the removed feature.

	build: update gnulib submodule to latest

2019-01-03  Bruno Haible  <bruno@clisp.org>

	diff: recognize file descriptors closed by the parent process on HP-UX
	* src/diff.c (compare_files): Use fcntl to distinguish a file
	descriptor closed by the parent process from a file descriptor
	that references /dev/null.

2019-01-01  Jim Meyering  <meyering@fb.com>

	maint: update all copyright dates via "make update-copyright"
	* gnulib: Also update submodule for its copyright updates.

2018-12-31  Jim Meyering  <meyering@fb.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.7
	* NEWS: Record release date.

	maint: distribute new file, init.cfg
	Otherwise, strip-trailing-cr would fail on a system without valgrind.
	* tests/Makefile.am (EXTRA_DIST): Include init.cfg.

2018-12-30  Dennis Lambe Jr  <malsyned@malsyned.net>

	diff: adjust ANSI escapes for compatibility with less -R
	GNU less can display ANSI-colored text with the -R flag, but this
	support has some limitations. One of them is that if an escape
	sequence starts on one line and ends on a different line, only the
	first line will be colored in less.

	As a result, when diff creates colored output with multi-line deletes
	or adds, less will only color the first line.

	This change resets ANSI color to the default at the end of
	each line and restarts it at the beginning of the next. It patches
	normal and context mode. Side-by-side already worked in my testing.
	* src/context.c (print_context_label, pr_context_hunk): As above.
	(pr_unidiff_hunk, print_context_header): Likewise.
	* src/normal.c (print_normal_hunk): Likewise.
	* tests/colors: Adjust existing tests to accommodate this.
	* NEWS (Improvements): Mention it.
	Proposed in http://bugs.gnu.org/31105

2018-12-29  Jim Meyering  <meyering@fb.com>

	tests: fix colors test on systems lacking fractional timestamp support
	* tests/colors: The .NNNNNNNNN suffix is not printed on some systems.
	Adapt the test to accommodate those systems.

	tests: strip-trailing-cr: avoid failure with ASAN
	Valgrind cannot operate on an ASAN-compiled binary.
	* tests/strip-trailing-cr (valgrind): Define as no-op when diff
	was compiled with sanitizer support.

2018-12-28  Jim Meyering  <meyering@fb.com>

	tests: add test for --strip-trailing-cr UMR bug
	* tests/strip-trailing-cr: New file. Test for today's bug fix.
	* tests/Makefile.am (TESTS): Add it.

	tests: import test infrastructure from coreutils
	* tests/init.cfg: New file, for require_valgrind_ definition (from coreutils).
	* tests/Makefile.am (PATH): Don't set stderr_fileno_ here, since it is
	now initialized in init.cfg.

2018-12-28  Paul Eggert  <eggert@cs.ucla.edu>
	    Jim Meyering  <jim@meyering.net>

	diff: fix UMR with --strip-trailing-cr
	Problem reported by Hongxu Chen (Bug#31935).
	* src/io.c (prepare_text): Strip trailing CR before
	doing the rest of the analysis.
	* NEWS: Mention the fix.

2018-12-28  Bruno Haible  <bruno@clisp.org>

	tests: colors: avoid test failure on AIX 7
	* tests/colors: Splice the argument into the printf format string.

2018-12-27  Bruno Haible  <address@hidden>

	maint: don't use an undocumented Autoconf macro
	* configure.ac: Use AC_CONFIG_HEADERS instead of AC_CONFIG_HEADER.

2018-12-23  Jim Meyering  <meyering@fb.com>

	build: avoid build failure with --enable-gcc-warnings and latest gcc
	* src/diff.c (usage): Assert that each line length is no longer than
	the minimum required size of 4095.  This lets newer gcc (currently
	9.0.0 20181219) infer that it need not issue this warning:
	diff.c:1012:19: error: '%.*s' directive output between 0 and 2147483647
	bytes may exceed minimum required size of 4095
	[-Werror=format-overflow=]
	1012 |        printf ("  %.*s", msglen, msg);

	build: update gnulib to latest; and bootstrap and init.sh

	build: make the autoconf-2.63 requirement explicit
	* configure.ac: AC_PREREQ: Require 2.63, not 2.59. And quote properly.
	Autoconf-2.63 has been required for some time via gnulib.
	This merely makes it explicit.

2018-12-20  Jim Meyering  <meyering@fb.com>

	maint: use https: in gnu mirror URL prefix, not http
	This appears in the generated release announcement message.
	* cfg.mk (url_dir_list): Use https: prefix, not http:.

2018-07-24  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: fix bug in -b diagnostic
	Problem reported by mancha (Bug#32249).
	* src/cmp.c (count_newlines): Restore old value of sentinel.
	* tests/cmp: Test for the bug.

	build: update gnulib submodule to latest

2018-05-14  Paul Eggert  <eggert@cs.ucla.edu>

	doc: prepend "GNU" to NAME in man pages
	Requested by RMS.
	* src/cmp.c, src/diff.c, src/diff3.c, src/sdiff.c:
	Prepend "GNU" to first comment, so that the man page says "GNU".

2018-04-20  Paul Eggert  <eggert@cs.ucla.edu>

	sdiff: port to mingw
	Problem reported by Ross Burton (Bug#31218).
	* src/sdiff.c (checksigs): Use ‘raise’, not ‘kill’.

2018-03-23  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2018-01-14  Jim Meyering  <meyering@fb.com>

	tests: fix quoting error in previous change
	* tests/colors: Double-quote $PATH.

2018-01-06  Jim Meyering  <meyering@fb.com>

	tests: port tests/colors to some env-munging shell
	* tests/colors: Also set PATH="$PATH" in env invocation.

	maint: update gnulib and copyright dates for 2018
	* gnulib: Update to latest.
	* all files: Run "make update-copyright".
	* bootstrap: Update from gnulib.

	maint: suppress gcc's new -Wcast-function-type in gnulib
	* configure.ac (WERROR_CFLAGS): Suppress gcc's new -Wcast-function-type
	warning in gnulib, because it would trigger on this:
	sig-handler.h:47:12: error: cast between incompatible function types\
	  from 'void (* const)(int,  siginfo_t *, void *)' \
	  {aka 'void (* const)(int,  struct <anonymous> *, void *)'} \
	  to 'void (*)(int)' [-Werror=cast-function-type]
	return (sa_handler_t) a->sa_sigaction;

2017-10-22  Jim Meyering  <meyering@fb.com>

	tests: add expected-failing test for minor subopimality
	In some unusual cases, diff -u prints suboptimal output.
	* tests/large-subopt: New test script.
	* tests/Makefile.am (TESTS): Add it.
	(XFAIL_TESTS): Add it here, too, to record that this test is
	currently expected to fail.
	* tests/large-subopt.in1, tests/large-subopt.in2: Inputs derived from
	those in http://bugs.gnu.org/28796

2017-09-23  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

2017-05-21  Jim Meyering  <meyering@fb.com>

	maint: make the announcement template Cc the devel- list
	* cfg.mk (announcement_Cc_): Define.

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.6
	* NEWS: Record release date.

2017-05-19  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

2017-05-18  Jim Meyering  <meyering@fb.com>

	maint: update to work with GCC7's -Werror=implicit-fallthrough=
	* src/system.h (FALLTHROUGH): Define.
	Use new FALLTHROUGH macro in place of comments
	* src/cmp.c: FIXME
	* src/diff3.c: FIXME
	* src/ifdef.c: FIXME
	* src/sdiff.c: FIXME
	* src/side.c: FIXME
	* src/util.c: FIXME

	gnulib: update to latest

2017-05-09  Jim Meyering  <meyering@fb.com>

	tests: new-file: closed-stdin: also ensure stdout was empty
	* tests/new-file: Also require that "out" be empty.

2017-05-06  Jim Meyering  <meyering@fb.com>

	maint: stop using @acronym{...} in texinfo sources
	* doc/diffutils.texi: Remove all uses of @acronym{...},
	per recommendation by Karl Berry.
	* cfg.mk (local-checks-to-skip): Remove exemption, enabling
	the @acronym{-prohibiting syntax-check rule.

2017-05-05  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: improve EOF diagnostic
	This improves on yesterday's change, following up on a
	remark by Jim Meyering (Bug#22816#21).
	* doc/diffutils.texi (Invoking cmp, cmp Options): Follow POSIX more
	closely in the documentation of the information appended to the EOF
	diagnostic.
	* src/cmp.c (cmp): Be more specific about the shorter file's length
	and fix some off-by-1 issues in reporting line counts.
	* tests/cmp: Adjust to match new behavior.
	Don't assume internal details about stdio buffering.

2017-05-04  Benno Schulenberg  <bensberg@justemail.net>

	diff: describe each --help option with a single string
	* src/diff.c: To ease translating, fuse four description pieces
	into two whole ones.  Also reword and rewrap one of them to fit
	within eighty characters.

2017-05-04  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: report prefix length when one file is shorter
	Requested by Dan Jacobson (Bug#22816).
	* NEWS:
	* doc/diffutils.texi (Invoking cmp, cmp Options): Document this.
	* src/cmp.c (cmp): Implement it.
	* tests/Makefile.am (TESTS): Add cmp.
	* tests/cmp: New file.

2017-05-02  Jim Meyering  <meyering@fb.com>

	tests: add test for latest fix
	* NEWS (Bug fixes): Describe it.
	* tests/invalid-re: New test for just-fixed bug.
	* tests/Makefile.am (TESTS): Add it.

	gnulib: update to latest

2017-04-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: don't crash if regexp is invalid
	Problem reported by Marcel Böhme in:
	http://lists.gnu.org/archive/html/bug-diffutils/2017-04/msg00002.html
	* src/diff.c (add_regexp): Exit if re_compile_pattern fails.

2017-03-24  julama  <julama@fake-box.com>

	tests: avoid false failure for unreadable /proc/cmdline
	* tests/brief-vs-stat-zero-kernel-lies: Use "test -r" rather than
	just "test -f".  This avoids a false test failure on a linux system
	with grsecurity and its GRKERNSEC_PROC_USER option enabled, for which
	/proc/cmdline is unreadable.  Reported in https://bugs.gnu.org/26155

2017-02-01  Jim Meyering  <meyering@fb.com>

	tests: avoid false failure with some shells on debian, freebsd
	* tests/colors: Move the TERM=dumb setting into the code run by
	"returns_", since some shells do not propagate envvar setting through
	to a use of a function like this.  That would cause this test to fail
	because results were colorized when they should not have been.
	Reported by Nelson Beebe.

2017-01-31  Jim Meyering  <meyering@fb.com>

	maint: add "introduced in 3.4" in latest NEWS entry
	* NEWS: Update.  Also, thanks to Nelson Beebe for reporting this.

	diff: avoid UMR with ---presume-output-tty
	* src/diff.c (main): Always define presume_output_tty.
	Otherwise, it would be read uninitialized.
	Introduced in v3.3-45-g17e2698
	* NEWS (Bug fixes): Mention it.

	gnulib: update to latest; and update bootstrap and init.sh

	maint: change "time stamp" to "timestamp" globally
	This avoids a new syntax-check failure.
	* ChangeLog-2008: Perform that change.
	* doc/diffutils.texi: Likewise.
	* NEWS: Likewise.
	* cfg.mk: Update the old news hash accordingly.

2017-01-01  Jim Meyering  <meyering@fb.com>

	maint: update gnulib and copyright dates for 2017
	* gnulib: Update to latest.
	* all files: Run "make update-copyright".

2016-11-08  Jim Meyering  <meyering@fb.com>

	tests: use "returns_" rather than explicit comparison with "$?"
	* tests/colors: Use "returns_ 1" rather than testing $? = 1
	* tests/basic: Likewise.
	* tests/binary: Likewise.
	* tests/filename-quoting: Likewise.
	* tests/function-line-vs-leading-space: Likewise.
	* tests/ignore-matching-lines: Likewise.
	* tests/label-vs-func: Likewise.
	* tests/new-file: Likewise.
	* tests/no-dereference: Likewise.
	* tests/no-newline-at-eof: Likewise.
	* tests/stdin: Likewise.

2016-10-25  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix big performance degradation in 3.4
	* NEWS, doc/diffutils.texi (Overview): Document this.
	* src/analyze.c (diff_2_files): Restore too_expensive heuristic,
	but this time with a floor that is 16 times the old floor.  This
	should fix Bug#16848, by generating good-quality output for its
	test case, while not introducing Bug#24715, by running nearly as
	fast as diff-3.3 for that test case.

	build: update gnulib submodule to latest

2016-10-16  Jim Meyering  <meyering@fb.com>

	maint: use die rather than error
	Use "die (N, ..." rather than "error (N, ..." whenever N is a nonzero
	constant.  That lets the compiler know that control never goes beyond
	that point, and thus makes unnecessary the occasional following
	"abort ();" or "break;" statement we have historically added to inform
	static analysis tools of this aspect of "error" semantics.
	* src/die.h: New file.
	* src/Makefile.am (noinst_HEADERS): Add it.
	* src/cmp.c: Use die in place of error whenever the first
	argument is a nonzero constant.  Also remove any immediately-
	following call to abort, and include "die.h".
	* src/diff.c: Likewise.
	* src/diff3.c: Likewise.
	* src/sdiff.c: Likewise.
	* src/util.c: Likewise.

2016-10-02  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

	build: avoid GCC 7's new warnings
	* src/util.c (get_funky_string): Adjust comment so that GCC 7's
	-Wimplicit-fallthrough recognizes it.
	* src/diff3.c (main): Cast boolean MERGE to "int" to avoid this:
	diff3.c:341:25: error: '~' on a boolean expression \
	[-Werror=bool-operation]

2016-08-30  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

2016-08-29  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest, to port to upcoming GCC 7
	This fixes compilation errors when using gcc-7-to-be that were
	due to missing backslashes in gnulib's intprops.h and an API
	change in functions like __builtin_add_overflow.  This ports
	to GCC 7's newer built-in overflow-checking functions.

2016-08-28  Paul Eggert  <eggert@cs.ucla.edu>

	diff: don't assume ptrdiff_t <= long long int
	* src/system.h (printint, pI): Port to (theoretical) platforms
	where ptrdiff_t is wider than long long int (Bug#24311).

2016-08-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: port line numbers to mingw64
	Problem reported by Peter Rosin (Bug#24311).
	* src/system.h (printint, pI): New typedef and macro.
	All uses of 'long int' and "%l" in printf format replaced by
	'printint' and "%"pI respectively.
	* src/ifdef.c (do_printf_spec): Don't assume pI is length 1.

2016-08-20  Jim Meyering  <meyering@fb.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.5
	* NEWS: Record release date.

2016-08-16  Jim Meyering  <meyering@fb.com>

	build: arrange to build with -fno-common, when possible
	* configure.ac (WERROR_CFLAGS): Add -fno-common, when possible.
	This would have prevented the duplicate definition of
	presume_output_tty that was fixed in v3.4-10-gc2dc91f.

2016-08-16  Hanno Böck  <hanno@hboeck.de>

	diff: avoid duplicate definition of presume_output_tty
	* src/util.c (presume_output_tty): Remove this definition.
	The other is in diff.h.  Reported in https://bugs.gnu.org/24248

2016-08-14  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

	tests: diff3: work around missing seq on some systems
	* tests/diff3 (seq): Provide a seq replacement function,
	since at least AIX, SunOS 5.10, OpenBSD-5.8 lack it.
	Reported by Assaf Gordon in https://bugs.gnu.org/24227#8

2016-08-13  Jim Meyering  <meyering@fb.com>

	diff3: fix leaks, for real
	* src/diff3.c (struct diff_block)[lint]: Add member, n2.
	(free_diff_block, next_to_n2): New functions.
	* tests/diff3: Add more test coverage.

	maint: require that commit messages be of a certain form
	* bootstrap.conf (bootstrap_epilogue): Merge from coreutils, so that
	a local commit hook will now help enforce consistent commit messages.
	* Makefile.am (check-git-hook-script-sync): New rule, largely copied
	from coreutils.
	* scripts/git-hooks/commit-msg: New file, from coreutils, but
	with adapted list of program names.
	* scripts/git-hooks/applypatch-msg: New file, from git.
	* scripts/git-hooks/pre-applypatch: Likewise.
	* scripts/git-hooks/pre-commit: Likewise.

2016-08-13  Bastian Beischer  <bastian.beischer@rwth-aachen.de>

	diff3: fix heap use-after-free; add minimal diff3 test coverage
	Commit v3.3-42-g3b74a90, "FIXME: src/diff3: plug a leak" added an
	invalid use of free, leading to use-after-free in nearly any invocation
	of diff3.  Revert that commit.
	* NEWS (Bug fixes): Mention it.
	* tests/diff3: New file, to add minimal test coverage.
	* tests/Makefile.am (TESTS): Add it.
	Reported by Bastian Beischer in http://bugs.gnu.org/24210

2016-08-13  Jim Meyering  <meyering@fb.com>

	build: ignore texinfo build artifacts
	* .gitignore: Ignore texinfo artifacts in doc/.

	maint: diff3: remove an unreachable statement
	* src/diff3.c (main): Remove unreachable "return" after exit from main.

2016-08-08  Jim Meyering  <meyering@fb.com>

	diff: disable colorization for TERM=dumb
	* src/diff.c (main): With --color or --color=auto, when TERM is
	"dumb", disable colorization.  Suggested by Daniel Colascione.
	* NEWS (Bug fixes): Mention it.
	* tests/colors: Add a test that would fail without this change,
	yet passes with it.

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.4
	* NEWS: Record release date.

2016-08-06  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

	tests: tweak built_programs definition
	* tests/Makefile.am (built_programs): Adjust to work around what
	may be a problem due to interaction between Solaris 10's /bin/sh
	and an old version of GNU make. Reported by Dagobert Michelsen
	in https https://bugs.gnu.org/24137.

2016-08-02  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

	tests: skip a /proc/self-dependent test on the Hurd
	* tests/brief-vs-stat-zero-kernel-lies: The Hurd's /proc/self
	is not useful, so detect that and skip the test that requires it.
	Reported by Assaf Gordon in https://debbugs.gnu.org/24121#29

2016-08-01  Jim Meyering  <meyering@fb.com>

	tests/colors: fix portability problem with touch --date
	* tests/colors (epoch): Don't use GNU touch's --date=$epoch option.
	Use the portable -t 197001010000.00.
	Reported by Assaf Gordon in https://debbugs.gnu.org/24121#8

	build: Solaris 9: avoid link failure due to isblank use
	* bootstrap.conf (gnulib_modules): Add isblank, to avoid a link
	error on Solaris 9 Sparc.  Reported by Dagobert Michelsen.

	test: improve test infrastructure
	* tests/envvar-check: New file, copied from grep, with the addition
	of the EDITOR and GREP_OPTIONS envvar names.
	* tests/Makefile.am (EXTRA_DIST): Add it.
	(TESTS_ENVIRONMENT): Revamp, to be more like that of grep.

2016-07-31  Jim Meyering  <meyering@fb.com>

	maint: remove gl/lib/reg*.c.diff; no longer needed
	* gl/lib/regcomp.c.diff: Remove file, now that gnulib's
	regcomp.c compiles regex.c with -Wno-unused-parameter.
	* gl/lib/regex_internal.c.diff: This file induced a change to ensure
	that the "Idx" type was unsigned and to remove a few "VAR < 0"
	comparisons.  These days, it is probably fine to stay in sync with
	gnulib/glibc's copies
	of these files, so remove these patches, too.
	* gl/lib/regexec.c.diff: Likewise.
	Prompted by a report by Assaf Gordon and a suggestion from Paul Eggert.

	tests: colors: fix a portability problem and work around a shell bug
	* tests/colors (e): Fix a portability bug: use printf '\033'
	rather than '\e' to generate the required byte sequence, since
	for some shells (at least dash 0.5.8), the latter doesn't work.
	Work around a shell bug whereby "local tab=$(printf '\t')"
	would result in an empty value for "$tab": hoist each "tab"
	definition up/out of its function to global scope.
	Reported by Assaf Gordon in http://debbugs.gnu.org/24116#8

2016-07-23  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest; and tests/init.sh
	* gnulib: Update to latest.
	* init.sh: Update from gnulib.

2016-05-30  Jim Meyering  <meyering@fb.com>

	maint: arrange for "make distcheck" to work with unreleased automake
	* dist-check.mk (my-distcheck): Remove all .deps directories
	before performing the recursive comparison.

2016-05-24  Glenn Morris  <rgm@gnu.org>

	doc: fix a reference to emacs' emerge node
	* doc/diffutils.texi (Interactive Merging): Correct a reference to
	emacs' emerge node: s/emerge/Emerge/.
	This addresses http://debbugs.gnu.org/23613

2016-04-30  Jim Meyering  <meyering@fb.com>

	maint: arrange for better URLs in generated announcement message
	* cfg.mk (url_dir_list): Define.  I had been correcting the generated
	URLs by hand, just before the announcement.  This is better.

2016-03-15  Jim Meyering  <meyering@fb.com>

	maint: don't ignore gitlog-to-changelog failure
	* Makefile.am (gen-ChangeLog): Don't ignore failure of
	gitlog-to-changelog. This syncs to coreutils' copy of this rule.

2016-03-06  Giuseppe Scrivano  <gscrivano@gnu.org>

	diff: --color: fix an infinite recursion bug
	* src/diff.h (presume_output_tty): New extern variable.
	* src/diff.c (PRESUME_OUTPUT_TTY_OPTION): New enum.
	(group_format_option): Add '-presume-output-tty'.
	(main): Handle PRESUME_OUTPUT_TTY_OPTION.
	* src/util.c: New variable `presume_output_tty'.
	(check_color_output): Handle presume_output_tty.
	(set_color_context): Call process_signals only when color_context is
	not RESET_CONTEXT.
	* tests/colors: Check that diff doesn't crash when interrupted
	in the middle of a color sequence.

	Reported by Gisle Vanem in http://debbugs.gnu.org/22067

2016-01-31  Jim Meyering  <meyering@fb.com>

	maint: update prereq version of gettext
	* configure.ac: Increase designated gettext version to 0.19.2
	* bootstrap.conf (buildreq): Likewise.
	Remove now-unnecessary code to remove gettext-provided files.

	gnulib: update to latest

2016-01-01  Jim Meyering  <meyering@fb.com>

	FIXME: src/diff3: plug a leak

2016-01-01  Jim Meyering  <meyering@fb.com>

	maint: update copyright year, bootstrap, init.sh
	Run "make update-copyright" and then...

	* gnulib: Update to latest.
	* tests/init.sh: Update from gnulib.
	* bootstrap: Likewise.

2015-12-06  Jim Meyering  <meyering@fb.com>

	diff --brief no longer mistakenly reports diff. with 0-sized /proc/ files
	Normally, it is safe to assume two regular files are different when
	their st_size values are different.  However, that assumption may
	be invalid if either value is zero, as happens with files on Linux
	/proc and /sys file systems. Since skipping this optimization will
	usually cost very little (one read syscall, to read zero bytes),
	it is fine to accommodate those unusual files.
	* src/analyze.c (diff_2_files): Do not assume regular files differ
	just because their st_size values differ when one or more is 0.
	* src/diff.c (compare_files): Likewise.
	* tests/brief-vs-proc-stat-zero: New test.
	* tests/Makefile.am: Add it.
	* NEWS (Bug fixes): Describe it.
	Reported by Stephan Müller in http://debbugs.gnu.org/21942

	tests: arrange to print any skipped-test explanation to tty, too
	I noticed that when a test was skipped, the reason was not printed.
	This fixes it.  In coreutils, this variable is set in init.cfg,
	but there is no point in putting the definition so far from the
	code that chooses the file descriptor number in tests/Makefile.am.
	* tests/Makefile.am (TESTS_ENVIRONMENT) [stderr_fileno_]: Define
	here (to 9), right next to the companion "9>&2".

2015-11-29  Jim Meyering  <meyering@fb.com>

	build: add gperf to the list of required programs
	* bootstrap.conf (buildreq): Add gperf to the list.
	Reported by Stephan Müller in http://debbugs.gnu.org/21945

2015-11-29  Giuseppe Scrivano  <gscrivano@gnu.org>

	tests: Add tests for --color and --palette
	* tests/colors: New file.
	* tests/Makefile.am (TESTS): Add colors.

	doc: mention --color and --palette in NEWS

	diff: add --palette
	* bootstrap (gnulib_modules): Add 'argmatch'.
	* doc/diffutils.texi: Add documentation for --palette
	* src/diff.h (set_color_palette): New prototype.
	* src/diff.c (set_color_palette): New function.
	(color_palette): New variable.
	* src/utils.c: Include "argmatch.h".
	(struct bin_str): New struct.
	(struct color_ext_type): New struct.
	(color_indicator): New array.
	(indicator_name): New array.
	(indicator_no): New enum.
	(parse_state): New enum.
	(put_indicator): New function.
	(get_funky_string): New function. Copied from coreutils ls.
	(parse_diff_color):  New function. Copied from coreutils ls
	"parse_ls_color" function.
	(set_color_context): Use put_indicator instead of directly
	outputting the sequence.
	* po/POTFILES.in: Add 'lib/argmatch.c'

	diff: add support for --color
	* doc/diffutils.texi (diff Options): Add documentation for --color.
	Copied from coreutils ls --color.
	* src/context.c (pr_unidiff_hunk): Set the color context.
	(print_context_header): Likewise.
	(pr_context_hunk): Likewise.
	* src/diff.h (enum colors_style): New enum to record when to use colors.
	(colors_style): New variable to memorize the argument value.
	(set_color_context): Add function definition.
	* src/diff.c: : Define COLOR_OPTION.
	(specify_colors_style): New function.
	(longopts): Add --color.
	(main): Handle --color argument.
	(option_help_msgid): Add usage string for --color.
	* src/normal.c (print_normal_hunk): Set the color context.
	* src/side.c (print_1sdiff_line): Likewise.
	* src/util.c (print_1_line_nl): New function.
	(print_1_line): Make it a wrapper of 'print_1_line_nl'.
	(colors_enabled): New boolean variable.
	(begin_output): Call check_color_output once the output file is
	configured.
	(output_1_line): Periodically call `process_signals'.
	(caught_signals): New sigset_t.
	(colors_enabled): New boolean variable.
	(interrupt_signal): New sig_atomic_t.
	(stop_signal_count): New sig_atomic_t.
	(check_color_output): New function.
	(install_signal_handlers): Likewise. Copied from coreutils ls.
	(process_signals): Likewise.  Copied from coreutils ls.
	(set_color_context): New function.
	(sighandler): Likewise.  Copied from coreutils ls.
	(stophandler): Likewise.  Copied from coreutils ls.

2015-09-24  Andreas Grünbacher  <agruen@gnu.org>

	diff: Improve help text of option --label
	* src/diff.c (option_help_msgid): Improve help text of option --label.

2015-09-01  Jim Meyering  <meyering@fb.com>

	build: correct man-page generation rule
	The PATH was set incorrectly, so that the diff used by
	help2man was the one from $PATH, rather than the just-built
	one.
	* man/Makefile.am (bin_dir): New variable, to...
	(dist_man1_MANS): ...prepend ../src to PATH, not just "..".
	Also, add a test to ensure that each $(bin_dir)/$$base is
	executable, so this doesn't happen again.
	In http://debbugs.gnu.org/21023, Rodrigo Valiña
	Gutiérrez reported that diff.1 from the diffutils-3.3 tarball
	contained no description of the then-new --no-dereference option.

2015-07-10  Jim Meyering  <meyering@fb.com>

	doc: --no-dereference: improve wording/description
	* doc/diffutils.texi (Comparing Directories): Correct grammar.
	(diff Options) [--no-dereference]: Say a little more.

2015-01-01  Jim Meyering  <meyering@fb.com>

	maint: update copyright year ranges to include 2015; update gnulib

2014-12-12  KO Myung-Hun  <komh@chollian.net>

	diff: skip test if seek is not possible on OS/2 kLIBC
	This fixes the problem that 'diff - file' and 'cat file | diff - file'
	fail due to a seek failure with a message 'diff.exe: -: Invalid seek',
	because seek does not work on stdin and a pipe on OS/2 kLIBC.

	* src/io.c (sip): Set skip_test to true if seek is not possible on
	OS/2 kLIBC.

2014-12-09  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest

2014-12-09  KO Myung-Hun  <komh78@gmail.com>

	build: double-quote use of $PATH
	* man/Makefile.am (dist_man1_MANS): On OS/2, PATH_SEPARATOR is ';',
	but unquoted, that is interpreted as the shell's statement
	terminator.  Quote it.

2014-10-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix integer overflow problem with --tabsize
	Reported by Tobias Stoeckmann in: http://bugs.gnu.org/18857
	* src/diff.c (main): Don't overflow if INTMAX_MAX / 2 < tabsize.
	* tests/bignum: New file, to test for this bug.
	* tests/Makefile.am (TESTS): Add it.

2014-09-03  Paul Eggert  <eggert@cs.ucla.edu>

	doc: mention diff -B fix in NEWS

	diff: fix bug with diff -B and incomplete lines
	Reported by Navin Kabra via Eric Blake in:
	http://bugs.gnu.org/18402
	* src/util.c (analyze_hunk): Don't mishandle incomplete
	lines at end of file.
	* tests/no-newline-at-eof: Test for the bug.

	diff: fix performance bug with prefix computation
	* src/io.c (find_identical_ends): Fix performance bug:
	the test for when the prefix was needed messed up by
	the 2002-02-28 integer-overflow fixes, causing performance to be
	worse than it needed to be.

2014-08-23  Jim Meyering  <meyering@fb.com>

	gnulib: update to latest, as well as bootstrap

	maint: update copyright year range in texinfo documentation
	* doc/diffutils.texi: Update copyright.

2014-04-15  Jim Meyering  <meyering@fb.com>

	maint: update bug-reporting address
	* README: Change bug-gnu-utils@... to bug-diffutils@gnu.org.
	* doc/diffutils.texi: Likewise.
	Reported by Jamie Landeg Jones.

2014-03-26  Paul Eggert  <eggert@penguin.cs.ucla.edu>

	diff: fix two "..." typos in --help output
	* src/diff.c (option_help_msgid): Remove two "..." typos (Bug#17102).

2014-03-25  Paul Eggert  <eggert@cs.ucla.edu>

	doc: improve documentation about reading and stdin
	See Bug#17075.
	* doc/diffutils.texi (Comparison): Say that files need not be read.
	(Invoking diff): Remove confusing remark about 'diff - -'.
	It's not that useful, and it's not portable anyway.

2014-02-24  Paul Eggert  <eggert@cs.ucla.edu>

	diff, sdiff: minor integer overflow fixes
	* src/context.c (find_hunk):
	Simplify, now that 2 * context + 1 cannot overflow.
	* src/diff.c (main):
	* src/sdiff.c (interact):
	Don't rely on undefined behavior on signed integer overflow.
	* src/diff.c (main): Don't let contexts exceed CONTEXT_MAX.
	* src/system.h (CONTEXT_MAX): New macro.

	diff: fix bug with -I and overlapping hunks
	Problem reported by Vincent Lefevre in <http://bugs.gnu.org/16864>.
	* src/context.c (find_hunk): Threshold is CONTEXT only if
	the second change is ignorable.
	* tests/ignore-matching-lines: New test.
	* tests/Makefile.am (TESTS): Add it.

2014-02-23  Paul Eggert  <eggert@cs.ucla.edu>

	diff: remove TOO_EXPENSIVE heuristic
	Problem reported by Vincent Lefevre in <http://bugs.gnu.org/16848>.
	The simplest solution is to remove the TOO_EXPENSIVE heuristic
	that I added to GNU diff in 1993.  Although appropriate for
	circa-1993 hardware, these days the heuristic seems to be more
	trouble than it's worth.
	* NEWS: Document this.
	* doc/diffutils.texi (Overview): Modernize citations.
	Remove mention of TOO_EXPENSIVE heuristic.
	* src/analyze.c (diff_2_files): Adjust to TOO_EXPENSIVE-related
	API changes in gnulib's diffseq module.

	build: update gnulib submodule to latest

2014-01-31  Paul Eggert  <eggert@cs.ucla.edu>

	diff: exit with status 1, not 2, when binary files differ
	Problem reported by Vincent Lefevre in <http://bugs.gnu.org/16608>.
	* NEWS:
	* doc/diffutils.texi (Binary, Invoking diff): Document this.
	* src/analyze.c (briefly_report): Return void, not int.
	All uses changed.  Do not futz with exit status.  Simplify.
	* tests/binary: Adjust to match new behavior.

2013-09-26  Paul Eggert  <eggert@cs.ucla.edu>

	build: omit -Wsuggest-attribute=pure for lib
	* configure.ac (WARN_CFLAGS): Omit -Wsuggest-attribute=pure
	when compiling the lib subdirectory.  Reported for Fedora 19
	by Eric Blake in <http://bugs.gnu.org/15463>.

2013-08-22  Paul Eggert  <eggert@cs.ucla.edu>

	cmp, diff, sdiff: tune by using rawmemchr
	On my platform (AMD Phenom II X4 910e, Fedora 17 x86-64), this sped up
	'cmp -n 8GiB /dev/full /dev/zero' by a factor of 3.8, and
	'cmp -sn 8GiB /dev/full /dev/zero' by a factor of 1.8.
	* bootstrap.conf (gnulib_modules): Add rawmemchr.
	* src/cmp.c (cmp): Optimize the common case where buffers are the same,
	by using count_newlines rather than block_compare_and_count.
	(block_compare_and_count): Remove.
	(count_newlines): New function.
	* src/cmp.c (count_newlines):
	* src/io.c (prepare_text):
	* src/sdiff.c (lf_copy, lf_skip, lf_snarf):
	Use rawmemchr instead of memchr, for speed.

2013-08-12  Paul Eggert  <eggert@cs.ucla.edu>

	cmp: tune 'cmp a b' for GCC x86
	Performance problem reported by David Balažic in:
	http://lists.gnu.org/archive/html/bug-diffutils/2013-08/msg00013.html
	* src/system.h (word): Make it size_t, not uintmax_t.
	This sped up plain cmp 90% on my tests (GCC 4.8.1, x86).

2013-07-06  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2013-05-06  Stefano Lattarini  <stefano.lattarini@gmail.com>

	build: enable 'subdir-objects' automake option
	The future major Automake version (2.0, ETA at least one year from now)
	might enable that option unconditionally, so better get prepared in due
	time.

	* configure.ac (AM_INIT_AUTOMAKE): Adjust.
	(AM_PROG_CC_C_O): New, required by Automake up to 1.13.x when the
	'subdir-objects' is in use.

2013-04-28  Paul Eggert  <eggert@cs.ucla.edu>

	build: update gnulib submodule to latest

2013-04-03  Paul Eggert  <eggert@cs.ucla.edu>

	diff: fix bug with Asian file names
	Problem reported by Errembault Philippe in:
	http://lists.gnu.org/archive/html/bug-diffutils/2013-03/msg00012.html
	* NEWS: Document this.
	* src/dir.c (compare_names): Fall back on file_name_cmp if
	compare_collated returns 0, unless ignoring file name case.
	(diff_dirs): Don't bother with the O(N**2) stuff unless ignoring
	file name case.
	* tests/Makefile.am (TESTS): Add strcoll-0-names.
	* tests/strcoll-0-names: New file.

	diff: remove unnecessary decl
	* src/dir.c (compare_names_for_qsort): Remove declaration.
	Not needed now that we assume C89.

	diff: tune compare_names_for_qsort
	* src/dir.c (compare_collated): New function.
	(compare_names): Use it.
	(compare_names_for_qsort): Use it.  This is a bit more efficient
	as it can avoid a double invocation of file_name_cmp when
	file_name_cmp returns zero.

2013-03-30  Jim Meyering  <meyering@fb.com>

	doc: mention new option, --no-dereference in 3.3's NEWS
	* NEWS (New feeatures): Update 3.3's news to mention --no-dereference.
	Reported by Denis Excoffier.
	* Makefile.am (old_NEWS_hash): Update, since this modifies old, and
	normally-immutable NEWS.

2013-03-26  Paul Eggert  <eggert@cs.ucla.edu>

	tests: port to Solaris 10 /bin/sh
	* tests/Makefile.am (TESTS_ENVIRONMENT):
	Use "FOO=val; export FOO" rather than "export FOO=val",
	as the latter form doesn't work with Solaris /bin/sh.
	Problem found when trying to run "make check" on Solaris 10.

2013-03-24  Jim Meyering  <meyering@fb.com>

	maint: post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.3
	* NEWS: Record release date.

2013-03-23  Paul Eggert  <eggert@cs.ucla.edu>

	doc: fix menu typo
	* doc/diffutils.texi (Comparing Three Files): Fix out-of-order menu.
	Bug caught by Texinfo 5.0.

	maint: update build procedure to recent gettext etc.
	* bootstrap.conf (gnulib_modules): Add vararrays.
	(needed_gnulib_files, unnecessary_gettext_files): New vars.
	(bootstrap_post_import_hook): New function, to implement these vars.
	(excluded_files): Remove; 'bootstrap' no longer supports this.
	Its function is now performed by unnecessary_gettext_files.
	(buildreq): Update automake to 1.12.2, to avoid CVE-2012-3386.
	* configure.ac (AM_GNU_GETTEXT_VERSION): Bump from 0.17 to 0.18.2,
	to lessen the probability that we'll have outlandishly old files
	during a build.
	* m4/vararrays.m4: Remove from repository, as we now use the
	gnulib version.

2013-03-21  Jim Meyering  <jim@meyering.net>

	build: update gnulib to latest and adapt; update bootstrap, too
	Blindly updating to the latest from gnulib, bootstrap would
	fail due to failure of our local patches to apply.  Hence,
	these first two updates.
	* gl/lib/regex_internal.c.diff: Update offsets, so this patch
	applies to the latest from gnulib.
	* gl/lib/regex_internal.h.diff: Remove file.  No longer needed.
	* bootstrap: Update from gnulib.

2013-01-06  Paul Eggert  <eggert@cs.ucla.edu>

	tests: port to hosts lacking fmt, make -C
	* tests/Makefile.am (built_programs): Don't assume fmt works.
	Don't rely on 'make -C', either.

	maint: update .gitignore for recent gnulib
	* .gitignore: Add tests/*.trs and several *.h and *.sed files in lib,

2013-01-04  Jim Meyering  <jim@meyering.net>

	build: update gnulib submodule to latest

	maint: update all copyright year number ranges
	Run "make update-copyright".

2012-10-23  Eric Blake  <eblake@redhat.com>

	build: default to --enable-gcc-warnings in a git tree
	Anyone building from cloned sources can be assumed to have a new
	enough environment, such that enabling gcc warnings by default will
	be useful.  Tarballs still default to no warnings, and the default
	can still be overridden with --disable-gcc-warnings.
	* configure.ac (gl_gcc_warnings): Set default based on environment.

2012-10-03  Paul Eggert  <eggert@cs.ucla.edu>

	* doc/diffutils.texi (cmp Options): Document -l format better.

2012-09-10  Jim Meyering  <meyering@redhat.com>

	maint: use xasprintf in place of xmalloc+sprintf
	* bootstrap.conf (gnulib_modules): Add gnulib's xvasprintf module.
	* src/util.c: Include "xvasprintf.h".
	(begin_output): Use xasprintf in place of xmalloc+sprintf.

2012-09-10  Andreas Gruenbacher  <agruen@gnu.org>

	diff: encode file names with special characters
	* src/util.c (c_escape_char): New function.
	(c_escape): New function.
	(begin_output): Escape file names when needed.
	* src/context.c (print_context_header): New names parameter.
	(print_context_label): New name parameter.
	* src/diff.h (print_context_header): Change prototype.
	* tests/filename-quoting: New file.
	* NEWS: Document this change.

2012-08-30  Paul Eggert  <eggert@cs.ucla.edu>

	diff: silence GCC warning instead of slowing down
	* src/dir.c (find_dir_file_pathname): Use 'IF_LINT (volatile)' to
	silence the gcc warning, rather than using 'volatile', as the
	warning appears to be bogus.

2012-08-28  Jim Meyering  <meyering@redhat.com>

	diff: avoid possible longjmp-triggered misbehavior
	* src/dir.c (find_dir_file_pathname): gcc 4.8.0 20120825 reported
	that a local variable's value might be clobbered.  Declare "match"
	to be volatile.

	build: update gnulib, bootstrap and init.sh to latest

	maint: avoid new syntax-check failure due to @xref use
	* doc/diffutils.texi: Change several "; @xref{..." to ".  @xref{...",
	since @xref should start a sentence.

2012-05-15  Paul Eggert  <eggert@cs.ucla.edu>

	maint: remove ms subdirectory
	diffutils is now designed to build with Cygwin or MinGW.
	The old DJGPP stuff probably doesn't work anyway.
	* Makefile.am (SUBDIRS): Remove ms.
	* NEWS: Document this.
	* configure.ac (AC_CONFIG_FILES): Remove ms/Makefile.
	* ms/Makefile.am, ms/README, ms/config.bat, ms/config.sed:
	* ms/config.site: Remove.

2012-05-14  Paul Eggert  <eggert@cs.ucla.edu>

	maint: update bootstrap from gnulib
	* bootstrap: Update from gnulib.

	main: port subcommands to mingw
	Problem reported by Eli Zaretskii in
	<http://lists.gnu.org/archive/html/bug-gnu-utils/2012-05/msg00013.html>.
	Approach suggested by Bruno Haible as option (4) in
	<http://lists.gnu.org/archive/html/bug-gnu-utils/2012-05/msg00036.html>.
	* bootstrap.conf (gnulib_modules): Add system-quote.
	* src/diff3.c, src/sdiff.c, src/util.c:
	Include <system-quote.h>, not <sh-quote.h>.
	* src/diff3.c (read_diff):
	* src/sdiff.c (main, edit):
	* src/util.c (begin_output):
	Use system_quote_argv, for portability to Mingw.
	* src/sdiff.c (NUM_SIGS, handler_index_of_SIGINT): Now enum
	values, not macros; this is cleaner and avoids a GCC warning if
	!HAVE_WORKING_VFORK.
	* src/util.c (begin_output) [! HAVE_WORKING_FORK]: Do not use -f,
	for consistency with the HAVE_WORKING_FORK code.

	maint: update bootstrap from gnulib
	* bootstrap: Update from gnulib.

	maint: m4/gnulib-cache.m4 is not under version control
	This is like what coreutils does, and suppresses 'git status' chatter.
	* .gitignore: Add /m4/gnulib-cache.m4.

	Use binary mode when testing for binary files.
	This reverts the 2006-01-05 change and modernizes to the current API.
	Idea suggested by Eli Zaretskii in:
	http://lists.gnu.org/archive/html/bug-gnu-utils/2012-05/msg00066.html
	* src/cmp.c (main):
	* src/diff.c (main, compare_files):
	Use set_binary_mode rather than SET_BINARY.
	* src/diff.c (compare_files): Omit unnecessary use of O_BINARY.
	* src/io.c (sip): Sample unknown files in binary mode, to see
	whether they are binary.
	(read_files): Read binary files in binary mode.

	build: update gnulib submodule to latest

2012-05-13  Stefano Lattarini  <stefano.lattarini@gmail.com>

	build: omit obsolete AM_PROG_CC_STDC macro
	The Automake-provided macro 'AM_PROG_CC_STDC' has been superseded by
	the Autoconf-provided one 'AC_PROG_CC' since October 2002, and will
	be removed in the next major automake version.
	* configure.ac (AM_PROG_CC_STDC): Drop it.

2012-05-05  Jim Meyering  <meyering@redhat.com>

	diff: fix a typo that was always disabling the same_special_file macro
	* src/system.h (same_special_file): Correct cpp guard expression:
	s/HAVE_ST_RDEV/HAVE_STRUCT_STAT_ST_RDEV/.  Reported by Eli Zaretskii.

2012-04-17  Jim Meyering  <meyering@redhat.com>

	maint: update bootstrap from gnulib
	* bootstrap: Update from gnulib.

2012-03-07  Eric Blake  <eblake@redhat.com>

	usage: improve wording of --ignore-matching-lines
	* src/diff.c (option_help_msgid): Tweak wording.

2012-03-04  Paul Eggert  <eggert@cs.ucla.edu>

	doc: explain -I RE better in --help output
	* src/diff.c, src/sdiff.c (option_help_msgid): For -I RE,
	change "whose lines all match" to "all whose lines match" to avoid
	unintended interpretation.  Reported by Danijel Tasov in
	<http://bugs.debian.org/648411>.

2012-02-12  Paul Eggert  <eggert@cs.ucla.edu>

	sdiff: remove dependency on sigprocmask
	* bootstrap.conf (gnulib_modules): Remove sigprocmask.
	* src/sdiff.c (temporary_file): No need to invoke sigprocmask
	here, since the signal handler merely sets a flag.

2012-02-04  Paul Eggert  <eggert@cs.ucla.edu>

	diff: -N, --unidirectional-new-file now compare to "-" too
	* NEWS: Document this.
	* doc/diffutils.texi (Comparing Directories): Likewise.
	Also, document that these options work at the top level.
	* src/diff.c (compare_files): Treat EBADF like ENOENT, to handle
	the case where "-" is closed.  Allow the other file to be
	STDIN_FILENO, in case it's "-".
	* tests/Makefile.am (TESTS): Add new-file.
	* tests/new-file: New file.

2012-01-25  Paul Eggert  <eggert@cs.ucla.edu>

	maint: quote 'like this' or "like this", not `like this'
	This is in response to a recent change in the GNU coding standards,
	which now suggest quoting 'like this' or "like this", instead of
	`like this' or ``like this''.
	* HACKING, NEWS, README, README-hacking, TODO, doc/diagmeet.note:
	* doc/diffutils.texi, ms/config.bat, ms/config.site:
	* src/analyze.c, src/cmp.c, src/context.c, src/diff.c:
	* src/diff.h, src/diff3.c, src/dir.c, src/ifdef.c, src/io.c:
	* src/sdiff.c, src/side.c, src/system.h, src/util.c:
	* tests/help-version:
	Quote 'like this' or "like this" in commentary.
	* cfg.mk (old_NEWS_hash): Adjust to reflect new NEWS quoting.
	* man/help2man: Update to 1.40.4 version, with quoting fixed as above.
	* po/en.po: Remove translation involving `, as it's no longer needed.
	* src/cmp.c (try_help, specify_ignore_initial, usage, main):
	* src/diff.c (main, try_help, option_help_msgid, specify_value)
	(compare_files):
	* src/diff3.c (main, try_help, option_help_msgid, usage)
	(read_diff):
	* src/dir.c (compare_names):
	* src/sdiff.c (try_help, usage, check_child_status, main):
	* src/util.c (finish_output):
	* tests/help-version:
	Quote 'like this' in output.

	build: update gnulib submodule to latest

2012-01-12  Jim Meyering  <meyering@redhat.com>

	build: accommodate newer bootstrap from gnulib
	* bootstrap.conf (gnulib_tool_option_extras): Add both --symlink
	and --makefile-name=gnulib.mk.  Also remove now-obsolete $bt/ prefix.
	* bootstrap: Update from gnulib.
	* tests/init.sh: Update from gnulib.
	* lib/Makefile.am: Initialize numerous variables, so that
	generated code in gnulib.mk may use += to append to them.

	maint: avoid new syntax-check failure
	* src/diff.c (compare_files): Use STREQ, not strcmp.

2012-01-08  Bruno Haible  <bruno@clisp.org>

	New option --no-dereference.
	* src/diff.h (no_dereference_symlinks): New variable.
	* src/diff.c: Include xreadlink.h.
	(longopts): Add --no-dereference option.
	(main): Accept --no-dereference option.
	(option_help_msgid): Mention the --no-dereference option.
	(compare_files): If no_dereference_symlinks is true, use lstat()
	instead of stat(). Compare symbolic links by comparing their values.
	* bootstrap.conf (gnulib_modules): Add lstat, stat, xreadlink.
	* doc/diffutils.texi (Comparing Directories, diff Options): Mention the
	--no-dereference option.
	* tests/no-dereference: New file.
	* tests/Makefile.am (TESTS): Add it.

2012-01-01  Jim Meyering  <meyering@redhat.com>

	maint: update all copyright year number ranges
	Run "make update-copyright".

2011-12-14  Jim Meyering  <meyering@redhat.com>

	build: update to latest gnulib and adapt
	* tests/binary: Reverse arguments to compare to avoid failure of
	new syntax-check rule.
	* configure.ac: Use -Wno-format-nonliteral.
	Mark functions as pure of const, per recommendations enabled by
	new gcc -W options.  Use _GL_ATTRIBUTE_PURE and _GL_ATTRIBUTE_CONST.
	* lib/cmpbuf.h (buffer_lcm, block_compare):
	Apply pure and/or const attributes.
	* src/cmp.c (block_compare): Likewise.
	* src/context.c (find_hunk): Likewise.
	* src/diff.h (lines_differ): Likewise.
	* src/diff3.c (skipwhite): Likewise.
	* src/dir.c (dir_loop): Likewise.
	* src/util.c (find_change, find_reverse_change): Likewise.
	(translate_line_number): Likewise.

	build: stop distributing gzip'd releases;  xz is enough
	* configure.ac (AM_INIT_AUTOMAKE): Add no-dist-gzip.

2011-11-29  Jim Meyering  <meyering@redhat.com>

	tests: use "compare exp out", not "compare out exp"
	Likewise, when an empty file is expected, use "compare /dev/null out",
	not "compare out /dev/null". I.e., specify the expected/desired contents
	via the first file name.  Prompted by a suggestion from Bruno Haible
	in http://thread.gmane.org/gmane.comp.gnu.grep.bugs/4020/focus=29154

	Run these commands:

	  git grep -l -E 'compare [^ ]+ exp' \
	    |xargs perl -pi -e 's/\b(compare) (\S+) (exp\S*)/$1 $3 $2/'
	  git grep -l -E 'compare [^ ]+ /dev/null' \
	    |xargs perl -pi -e 's,\b(compare) (\S+) (/dev/null),$1 $3 $2,'

	But manually convert this one:

	  -compare out exp-$(echo $opt|tr ' ' _)
	  +compare exp-$(echo $opt|tr ' ' _) out

	and avoid an inappropriate change to cfg.mk.

2011-10-12  Stefano Lattarini  <stefano.lattarini@gmail.com>

	tests: use more portable fd redirection in TESTS_ENVIRONMENT
	* tests/Makefile.am (TESTS_ENVIRONMENT): Redirection with `exec 9>&2'
	is not portable to various Korn shells, and to (at least) HP-UX 11
	/bin/sh.  Use a more portable idiom.
	See http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/22488 for
	lots of discussion.

2011-10-11  Stefano Lattarini  <stefano.lattarini@gmail.com>

	tests: make test runner a script, not a shell function
	All the test scripts in the diffutils testsuite are shell scripts,
	so the current definition of TESTS_ENVIRONMENT, which adaptively
	run tests using either perl or the shell depending on their kind,
	is an overkill.

	Moreover, this change is required in order for the testsuite to
	continue to work with the new testsuite harness that is planned
	to be introduced in Automake 1.12 (which, as of the writing date,
	is still under development and in late alpha state).

	See also related discussion on bug-coreutils:
	 <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=8887>

	* tests/Makefile.am (TESTS_ENVIRONMENT): Remove definition of the
	`shell_or_perl_' shell function, which is not required anymore.
	(LOG_COMPILER): New, define to `$(SHELL)'.
	* tests/binary: Make executable.
	* tests/colliding-file-names: Likewise.
	* tests/excess-slash: Likewise.
	* tests/no-newline-at-eof: Likewise.

2011-10-04  Claudio Bley  <claudio.bley@gmail.com>

	portability: use SET_BINARY rather than xfreopen (NULL, ...
	* src/diff.c: Include binary-io.h, not xfreopen.h.
	(main): Use SET_BINARY (...) rather than xfreopen (NULL, X, ...),
	because the latter doesn't work on MinGW and crashes using MSVC.
	* src/cmp.c (main): Likewise.

2011-10-04  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

2011-09-02  Jim Meyering  <meyering@redhat.com>

	post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.2
	* NEWS: Record release date.

	build: update bootstrap and tests/init.sh from gnulib
	* bootstrap: Update from gnulib.
	* tests/init.sh: Likewise.

	build: update gnulib submodule to latest

2011-09-01  Jim Meyering  <meyering@redhat.com>

	doc: diffutils' texi-derived doc may now be in debian's "main" section
	* NEWS (Packaging): Mention the "no front/back-cover" change.

2011-08-14  Jim Meyering  <meyering@redhat.com>

	maint: avoid new "make sytnax-check" failure.
	* src/diff.h (find_dir_file_pathname): Mark declaration with "extern"
	keyword, in order to placate the tight-scope syntax check.

2011-08-14  Paul Eggert  <eggert@cs.ucla.edu>

	* src/io.c (find_and_hash_each_line): Refactor for brevity.

2011-08-14  Roland McGrath  <roland@hack.frob.com>

	diff, sdiff: new option --ignore-trailing-space (-Z)
	Derived from Roland McGrath's patch (dated June 2004!) in:
	http://lists.gnu.org/archive/html/bug-gnu-utils/2004-07/msg00000.html
	* NEWS:
	* doc/diffutils.texi (White Space, Blank Lines)
	(sdiff Option Summary, diff Options, sdiff Options): Document -Z.
	* src/diff.h (IGNORE_TRAILING_SPACE)
	(IGNORE_TAB_EXPANSION_AND_TRAILING_SPACE): New constants, for -Z.
	* src/diff.c (shortopts, longopts, main, option_help_msgid):
	* src/sdiff.c (longopts, option_help_msgid, main):
	* src/io.c (find_and_hash_each_line):
	* src/util.c (lines_differ, analyze_hunk): Support -Z.

2011-08-13  Paul Eggert  <eggert@cs.ucla.edu>

	* bootstrap.conf (gnulib_modules): Remove timegm.
	This fixes a problem noted by Andreas Schwab in:
	http://lists.gnu.org/archive/html/bug-diffutils/2011-08/msg00035.html

2011-08-13  Tim Waugh  <twaugh@redhat.com>

	diff: --ignore-file-name-case now applies at top level too
	Derived from Tim Waugh's patch in:
	http://lists.gnu.org/archive/html/bug-diffutils/2011-08/msg00034.html
	* NEWS, doc/diffutils.texi (diff Options): Document this.
	* src/diff.c (compare_files): Implement this, by using
	find_dir_file_pathname.
	* src/diff.h (find_dir_file_pathname): New decl.
	* src/dir.c: Include filenamecat.h.
	(find_dir_file_pathname): New function.

2011-08-13  Paul Eggert  <eggert@cs.ucla.edu>

	* .gitignore: Add lib/unistr, lib/unused-parameter.h.

2011-08-10  Jim Meyering  <meyering@redhat.com>

	post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.1
	* NEWS: Record release date.

	build: use largefile module and update to latest gnulib
	* configure.ac: Remove AC_SYS_LARGEFILE, subsumed by ...
	* bootstrap.conf (gnulib_modules): ...this.  Use largefile module.
	* gnulib: Update to latest.

2011-08-08  Santiago Vila  <sanvila@unex.es>

	doc: insert comma in --help line for --ignore-space-change (-b)
	* src/diff.c (option_help_msgid): Insert omitted comma between
	"-b" and "--ignore-space-change".  (tiny change)

2011-08-04  Jim Meyering  <meyering@redhat.com>

	doc: relax restriction on front-cover and back-cover texts
	* doc/diffutils.texi (copying): Relax restriction on front-cover
	and back-cover texts (just as m4 did here:
	http://git.savannah.gnu.org/cgit/m4.git/commit?id=ee1e92ec).
	Reported by Santiago Vila.  Fix suggested by Eric Blake.

2011-08-03  Jim Meyering  <meyering@redhat.com>

	tests: update init.sh from gnulib
	* tests/init.sh: Update from gnulib.

	build: update gnulib submodule to latest

2011-07-03  Jim Meyering  <meyering@redhat.com>

	maint: remove inclusion of unused header, for "make syntax-check"
	* src/diff3.c: Don't include <inttostr.h>.  Not used.
	* src/context.c: Likewise.

2011-06-19  Jim Meyering  <meyering@redhat.com>

	build: don't require perl when building from a tarball
	But do ensure -- in all other circumstances -- that the man/*.1
	files are rebuilt whenever the version number changes.
	* configure.ac (SRC_VERSION_C): Define.
	* man/Makefile.am (dist_man1_MANS): Rename from $(man1_MANS),
	so that we distribute those pesky man/*.1 files.
	(EXTRA_DIST): Reflect name change.
	(MAINTAINERCLEANFILES): Define this, not DISTCLEANFILES,
	now that these generated files are distributed.
	($(dist_man1_MANS)): Depend on $(SRC_VERSION_C), so we get the
	full dependency when not building from a tarball.

2011-06-13  Jim Meyering  <meyering@redhat.com>

	doc: do not distribute generated man/*.1 man files
	* man/help2man: New file.
	* man/Makefile.am: Use $(srcdir)/help2man.
	Convert $(dist_man1_MANS) to $(man1_MANS), to tell automake
	not to distribute the generated man/*.1 files.  Now they're
	generated at build-from-tarball time.
	($(man1_MANS)): Depend on version.c, so that man pages are
	regenerated whenever the version string changes.

	build: ccache works better without embedded version strings
	* src/Makefile.am: Generate version.c and version.h and put the
	new symbol in a tiny library to be used by each program.
	(LDADD): Add the new library.
	* src/cmp.c (main): Use Version, not PACKAGE_VERSION, so the .o
	file does not change with each commit-derived version increment.
	* src/diff.c (main): Likewise.
	* src/diff3.c (main): Likewise.
	* src/sdiff.c (main): Likewise.
	* src/system.h: Include "version.h".
	* .gitignore: Add version.[ch]

2011-06-12  Jim Meyering  <meyering@redhat.com>

	doc: ensure each program has a man/*.x file: add "SEE ALSO" references
	* man/cmp.x: New file.
	* man/diff3.x: New file.
	* man/sdiff.x: New file.
	* man/diff.x: Add xrefs to the other three programs, and to patch.
	* man/Makefile.am (EXTRA_DIST): List new files.
	(cmp.1, diff3.1, sdiff.1): Depend on each .x file.

	doc: rename diff.texi to diffutils.texi
	This makes the .texi basename the same as the package name,
	which is consistent with most other GNU packages.
	* doc/diffutils.texi: Rename from...
	* doc/diff.texi: ...removed.
	* doc/Makefile.am (info_TEXINFOS): Reflect name change.
	(diffutils_TEXINFOS): Likewise.
	* cfg.mk (gendocs_options_): Remove this customization.  It is no
	longer needed, now that the .texi name matches that of the package.
	* man/Makefile.am ($(dist_man1_MANS)): Remove now-unnecessary sed
	filter.
	* README: Update references to diffutils.texi etc. here, too.
	* .gitignore: Update here, too.
	Suggested by Karl Berry.

2011-06-08  Karl Berry  <karl@freefriends.org>

	cmp, diff, diff3, sdiff: edit and align --help text.
	* cmp.c (option_help_msgid, usage),
	* diff.c (option_help_msgid, usage),
	* diff3.c (option_help_msgid, usage),
	* sdiff.c (option_help_msgid, usage): align descriptions in the --help
	output and slightly edit content.

2011-05-27  Paul Eggert  <eggert@cs.ucla.edu>

	diff: don't use locales after local-specific sorting fails
	* src/dir.c (compare_names): Don't invoke strcasecmp if
	locale-specific sorting fails, because POSIX.1-2008 says strcasecmp
	has unspecified behavior outside the POSIX locale.  See:
	http://lists.gnu.org/archive/html/bug-diffutils/2011-05/msg00008.html

	bootstrap: Avoid multithreading.
	* bootstrap.conf (gnulib_tool_option_extras):
	Add "--avoid=localename --avoid=lock", because we don't want to
	bring in the multithreading code that recent gnulib changes would
	otherwise bring in.
	(excluded_files): Remove m4/lock.m4; no longer needed, now that
	we use --avoid=lock.

	build: update gnulib submodule to latest

2011-05-23  Karl Berry  <karl@gnu.org>

	maint: update README-hacking
	* README-hacking: Update a la coreutils for git, etc.

2011-05-23  Jim Meyering  <meyering@redhat.com>

	maint: update gnulib to latest with accompanying tight-scope tweaks
	* cfg.mk: Include $(srcdir)/dist-check.mk using "-include",
	to accommodate the new sc_tight_scope rule.
	(_gl_TS_extern): Define, to tell gnulib's tight_scope rule that
	headers here mark externs with "XTERN".
	* gnulib: Update to latest.

2011-05-18  Jim Meyering  <meyering@redhat.com>

	maint: use gnulib's new readme-release module
	* bootstrap.conf (gnulib_modules): Add readme-release.
	(bootstrap_epilogue): Add the recommended perl one-liner.
	* README-release: Remove file; it is now generated from gnulib.
	* .gitignore: Add it.

	build: update gnulib submodule to latest

	maint: prepare for the tight-scope check
	* src/diff.h: Mark function declarations with "extern" in
	preparation for the tight-scope check.
	(ignore_white_space): Separate enum decl from declaration
	of this variable.
	* src/Makefile.am (diff_SOURCES): Move diff.h from here to ...
	(noinst_HEADERS): ...here.
	For convenience, since the tight-scope rule uses $(noinst_HEADERS).

	maint: don't use now-removed gnulib "exit" module
	* bootstrap.conf (gnulib_modules): Remove "exit" module.
	It no longer exists.

2011-03-26  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

	* .x-sc_space_tab: Remove file.  Instead, ...
	* cfg.mk (exclude_file_name_regexp--sc_space_tab): ...define this.

	maint: fix typo in unused rule
	* cfg.mk (config-save): Fix typo: add leading "_" in variable name.

2011-03-18  Jim Meyering  <meyering@redhat.com>

	doc: add a reference to wdiff(1) from diff.1
	* man/diff.x: New file, to add "SEE ALSO" reference to wdiff(1).
	* man/Makefile.am (diff.1): Depend on diff.x.
	($(dist_man1_MANS)): Tell help2man to include diff.x.
	(EXTRA_DIST): Add diff.x.
	Suggestion from Dan Jacobson in http://bugs.debian.org/613319

2011-03-18  Eric Blake  <eblake@redhat.com>

	docs: info should mention -L
	* doc/diff.texi (diff Options): Document -L.

	docs: diff --help should mention -L
	* src/diff.c (option_help_msgid): Document -L.

2011-02-15  Jim Meyering  <meyering@redhat.com>

	doc: speak of the --test (-a) option, not "the -a or --test option"
	Convert using this command:
	perl -pi -e \
	  's/(\@option{-.}) or (\@option{--.*?}) option/$2 ($1) option/' \
	  doc/diff.texi
	Then convert some more with this:
	perl -pi -e \
	    's/the (\@option{-.}) or (\@option{--.*?})$/the $2 ($1)/' \
	  doc/diff.texi
	Then convert more manually.

	Suggested by Dan Jacobson

2011-01-24  Jim Meyering  <meyering@redhat.com>

	maint: remove all uses of vfork: use fork instead
	Our use of vfork now provokes warnings from gcc-4.6.0.
	Also, vfork is no longer even specified by POSIX.1-2008.
	* src/diff3.c (read_diff): Change each use of vfork to "fork".
	Remove #ifdef'd code.
	* src/util.c (begin_output, finish_output): Likewise.
	* src/sdiff.c (cleanup, main, edit): Likewise.
	(handler_index_of_SIGPIPE): Remove now-unused definition.
	* src/system.h: Don't include <vfork.h>.
	(vfork): Remove definition.
	* ms/config.site: Remove reference to vfork cache variable.

	tests: avoid newer but less-portable tail option syntax
	* tests/function-line-vs-leading-space: Use sed -n '3,$p' rather than
	tail -n+3.  Older versions of tail do not accept that newer syntax.
	Reported by Sudhakara Peram.

	tests: fix an erroneous test
	On most systems, like-named files were compared, by luck.
	However, on others, different-named files would be compared
	since their names were being treated as equal -- but they had
	different content, so the test would fail.
	* tests/colliding-file-names: Use different sets of file names
	in d1 and d2 so that they cannot accidentally match.
	Put the same line in each test file.  This is required
	when files named e.g., abc and ABC are compared.
	This test was failing on a NixOS 86_64-darwin system.

	build: update gnulib submodule to latest

	tests: fix typo that silently disabled all tests
	* tests/Makefile.am (TESTS): Fix typo: s/jESTS/TESTS/

2011-01-23  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

	maint: avoid new syntax-check failure
	* src/diff.c (specify_value): Use !STREQ(...), not strcmp(...) != 0.
	* src/diff3.c (main): Likewise.

2011-01-03  Jim Meyering  <meyering@redhat.com>

	maint: update copyright year ranges to include 2011
	Run "make update-copyright", so "make syntax-check" works in 2011.

	build: update gnulib submodule to latest

2010-12-16  Paul Eggert  <eggert@cs.ucla.edu>

	bootstrap: adjust to recent gnulib changes
	* bootstrap.conf (excluded_files): Do not exclude m4/size_max.m4
	and m4/xsize.m4 when using an external gettext, since they are
	now needed by other gnulib modules.

2010-12-16  Jim Meyering  <meyering@redhat.com>

	doc: add contributor guidelines: HACKING
	* HACKING: New file, copied 99% from the one in grep's repository.

2010-10-09  Jim Meyering  <meyering@redhat.com>

	maint: describe policy on copyright year number ranges
	* README: Mention coreutils' long-standing policy on use of M-N
	ranges in copyright year lists.  Requested by Richard Stallman.

2010-09-04  Jim Meyering  <meyering@redhat.com>

	maint: adjust init.sh use to conform
	* tests/help-version: Use one line: "${srcdir=.}/init.sh"; ...
	* tests/basic: Likewise.
	* tests/binary: Likewise.
	* tests/colliding-file-names: Likewise.
	* tests/excess-slash: Likewise.
	* tests/function-line-vs-leading-space: Likewise.
	* tests/help-version: Likewise.
	* tests/label-vs-func: Likewise.
	* tests/no-newline-at-eof: Likewise.
	* tests/stdin: Likewise.

	maint: avoid shadowing warning
	* src/dir.c (diff_dirs): Rename shadowed local cmp to "c".

2010-09-03  Jim Meyering  <meyering@redhat.com>

	build: use gettext-h, not gettext
	* bootstrap.conf (gnulib_modules): Use gettext-h, not gettext.
	The latter is overkill for a package that uses
	AM_GNU_GETTEXT([external]...

	build: update build/test tools from gnulib
	* bootstrap: Update from gnulib.
	* tests/init.sh: Likewise.

	build: update gnulib submodule to latest

2010-08-14  Jim Meyering  <meyering@redhat.com>

	diff -r: avoid printing excess slashes in concatenated file names
	* bootstrap.conf (gnulib_modules): Add filenamecat.
	* src/diff.c: Include "filenamecat.h".
	(compare_files): Use file_name_concat, rather than dir_file_pathname.
	* src/util.c (dir_file_pathname): Remove now-unused function.
	* src/diff.h: Remove its declaration.
	* tests/excess-slash: New script to test for this.
	* tests/Makefile.am (TESTS): Add it.
	Forwarded by Santiago Vila from <bugs.debian.org/586301a>,
	reported by Jari Aalto.

2010-08-12  Paul Eggert  <eggert@cs.ucla.edu>

	diff: avoid spurious diffs when two distinct dir entries compare equal
	Problem reported by Christoph Anton Mitterer in:
	http://lists.gnu.org/archive/html/bug-diffutils/2010-08/msg00000.html

	* NEWS: Mention this bug fix.
	* src/dir.c (compare_names_for_qsort): Fall back on file_name_cmp
	if two distinct entries in the same directory compare equal.
	(diff_dirs): Prefer a file_name_cmp match when available.
	* tests/Makefile.am (TESTS): New test colliding-file-names.
	* tests/colliding-file-names: New file.

2010-05-09  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

	build: don't define macros that gnulib provides
	* bootstrap.conf (gnulib_modules): Add signal, stdint.
	* lib/cmpbuf.c (SA_RESTART, SA_INTERRUPT): Remove definitions.
	(SIZE_MAX, PTRDIFF_MAX): Likewise.
	Include <stdint.h>.
	* src/system.h (WEXITSTATUS, WIFEXITED): Remove definitions.
	(SA_RESTART, SA_INTERRUPT): Likewise.

	build: rely on gnulib's sigprocmask module
	* src/sdiff.c: Remove #if-!HAVE_SIGPROCMASK-guarded code.
	* bootstrap.conf (gnulib_modules): Add sigprocmask.

2010-05-04  Jim Meyering  <meyering@redhat.com>

	doc: README-release: don't mention To:, Cc:, etc announcement headers,
	now that those are supplied automatically via gnulib's maint.mk.
	* README-release: sync with coreutils.

	maint: teach web-doc-generating code how to do its job
	* cfg.mk (gendocs_options): Define, so that gendocs.sh knows
	the name of our texinfo source file.
	* gnulib: Update to latest, for new gnu-web-doc-update and maint.mk.

2010-05-03  Jim Meyering  <meyering@redhat.com>

	doc: update release procedure
	* README-release: Rearrange slightly: post the announcement to
	Savannah first, so you can include a link to that post in the email.
	Sync a few details from coreutils' README-release.

	post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 3.0
	* NEWS: Record release date.

	build: update gnulib submodule to latest

2010-04-30  Jim Meyering  <meyering@redhat.com>

	build: use gnulib's sys_wait module
	* bootstrap.conf (gnulib_modules): Use gnulib's sys_wait module,
	now that we assume its presence.

	build: update gnulib submodule to latest
	* bootstrap: Also update from gnulib.
	* tests/init.sh: Likewise

	maint: remove now-useless #if HAVE_HEADER_H guards
	* src/system.h: Include <sys/wait.h> unconditionally,
	now that gnulib guarantees its presence.
	* lib/cmpbuf.c: Likewise for <unistd.h> and <inttypes.h>.

2010-04-16  Jim Meyering  <meyering@redhat.com>

	tests: use original no-newline-at-eof test, but with -U1, not -U2
	* tests/no-newline-at-eof: Revert to the smaller test, but with
	-U1 rather than -U2, since that actually triggers the bug.

2010-04-16  Paul Eggert  <eggert@cs.ucla.edu>

	Followon improvements for the fix for Debian bug 577832.
	* src/io.c (find_and_hash_each_line): Omit the inserted newline in
	a simpler way.
	* tests/no-newline-at-eof: Fix the test case so that it rejects
	the old, buggy behavior.

2010-04-16  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

	tests: test for the no-newline-at-EOF bug
	* tests/no-newline-at-eof: New file.
	* tests/Makefile.am (TESTS): Add it.

2010-04-16  Jim Meyering  <meyering@redhat.com>

	diff: fix a regression when at least one input lacks a newline-at-EOF,
	and the final hunk plus context-length aligns exactly with the end
	of the newline-lacking file.  Diff would fail to output the required
	"\ No newline at end of file" line, thus rendering the output invalid.
	This bug appears to have been introduced by 2006-05-07
	commit 58d0483b, "(find_identical_ends): Fix huge performance bug...",
	at least to the extent that reverting that change fixes the bug.
	Considering the stated effect of that change and lack of metrics,
	reverting it is not an option, so here we take a more direct approach.

	Given these inputs,

	    printf '\n1'>a; printf '\n0\n\n1'>b

	and running diff like this:

	    ./diff -U1 a b

	for input file "b", the pointer, files[1].linbuf[4][-1], to
	the last byte on the final line was mistakenly pointing at the
	sentinel newline at EOF, rather than at the preceding byte.

	  (gdb) p files[1].linbuf[4][-1]
	  $3 = 10 '\n'

	Thus, this test in the final print_1_line call:

	  if ((!line_flag || line_flag[0]) && limit[-1] != '\n')
	    fprintf (out, "\n\\ %s\n", _("No newline at end of file"));

	would fail, because limit[-1] (which is files[1].linbuf[4][-1])
	was mistakenly '\n', rather than the desired '1'.

	My first thought was simply to adjust the final linbuf[line] setting,
	at the end of io.c's find_and_hash_each_line function function:

	       if (p == bufend)
	-       break;
	+       {
	+         if (current->missing_newline)
	+           --linbuf[line];
	+         break;
	+       }

	But that would make diff misbehave with this input
	(same as above, but with a newline appended to "a"),

	    printf '\n1\n'>a; printf '\n0\n\n1'>b
	    ./diff -U1 a b

	due to the block (100 lines above) that is triggered in that case
	(but not in the both-files-missing-newline case):

	      if (p == bufend
	          && current->missing_newline
	          && ROBUST_OUTPUT_STYLE (output_style))
	        {
	          /* This line is incomplete.  If this is significant,
	             put the line into buckets[-1].  */
	          if (ignore_white_space < IGNORE_SPACE_CHANGE)
	            bucket = &buckets[-1];

	          /* Omit the inserted newline when computing linbuf later.  */
	          p--;
	          bufend = suffix_begin = p;
	        }

	Note how "p" is decremented and "bufend" adjusted.
	When that happens, we certainly don't want to decrement
	"bufend" yet again.

	Since there is no other way to determine at the end whether "bufend"
	was already decremented, add a new variable to serve as witness.

	* NEWS (Bug fixes): Mention it.
	Reported by Timo Juhani Lindfors in http://bugs.debian.org/577832.
	Forwarded by Santiago Vila.

2010-04-16  Jim Meyering  <meyering@redhat.com>

	tests: update init.sh from gnulib
	* tests/init.sh: Update from gnulib.

2010-04-08  Jim Meyering  <meyering@redhat.com>

	build: include cfg.mk and dist-check.mk in the distribution tarball
	* Makefile.am (EXTRA_DIST): Add cfg.mk and dist-check.mk.

	maint: update to latest gnulib
	* cfg.mk (sc_cross_check_PATH_usage_in_tests): Remove rule,
	now that it's in gnulib's maint.mk.
	* gnulib: Update to latest.

2010-04-07  Jim Meyering  <meyering@redhat.com>

	tests: make new PATH-crosschecking syntax-check tighter
	* cfg.mk (sc_cross_check_PATH_usage_in_tests): Use grep's -x (match
	entire line) option with -F.

	tests: pull latest help-version from gzip
	* tests/help-version: Update from gzip.
	* Makefile.am (TESTS_ENVIRONMENT): Export VERSION,
	as required for this new help-version script.

	tests: add syntax-check rule to verify that tests use proper PATH
	* cfg.mk (sc_cross_check_PATH_usage_in_tests): New rule, that is
	useful only in conjunction with the help-version script.

	tests: use path_prepend_ consistently; remove unnecessary VERBOSE check
	* tests/basic: Likewise.
	* tests/binary: Likewise.
	* tests/function-line-vs-leading-space: Likewise.
	* tests/label-vs-func: Likewise.
	* tests/stdin: Likewise.

2010-04-06  Eric Blake  <eblake@redhat.com>

	maint: ignore generated files
	* .gitignore: Ignore recent gnulib additions.

	maint: update to latest bootstrap
	* bootstrap: Copy from gnulib/build-aux.

2010-04-05  Jim Meyering  <meyering@redhat.com>

	tests: get latest init.sh from gnulib
	* tests/init.sh: Update from gnulib.

	build: update gnulib submodule to latest; adapt
	* cfg.mk (local-checks-to-skip): Add new sc_texinfo_acronym, to skip it.

	diff -F/-p: don't depend on locale-specific white-space definition
	* src/context.c: Include "c-ctype.h".
	Use c_isspace, not isspace.

2010-03-18  Jim Meyering  <meyering@redhat.com>

	tests: exercise new behavior of -F RE
	* tests/function-line-vs-leading-space: New file.
	* tests/Makefile.am (TESTS): Add it.

2010-03-18  Yannick Moy  <yannick.moy@adacore.com>

	with -F or -p, emit better function lines: no leading white space
	* src/diff.c (print_context_function): For languages like Ada
	that allow local functions and procedures, the plain context
	function line may start with enough blank characters that the
	function name does not get completely printed in the 40
	characters limit.  This patch solves this problem by removing
	these useless initial blank characters.
	* NEWS (Changes in behavior): Mention this change.

2010-03-17  Jim Meyering  <meyering@redhat.com>

	build: don't require a specific version of help2man
	* bootstrap.conf (buildreq): Bootstrap can't deal with it,
	perhaps because the command name contains a digit.

	build: make bootstrap ensure that help2man is available
	* bootstrap.conf (buildreq): Add help2man.

2010-02-23  Jim Meyering  <meyering@redhat.com>

	tests: test for the "Binary files A and B differ" diagnostic
	* tests/binary: New script.
	* tests/Makefile.am (TESTS): Add it.

	revert 2002 change that removed "Binary " from "files A and B differ"
	With this change, "printf '\0'|diff - /dev/null" now prints
	"Binary files - and /dev/null differ" once again.
	This reverts 2002-06-28 commit a352f0980,
	"(briefly_report): Don't say "Binary files differ", ...".
	* src/analyze.c (briefly_report): Do include the "Binary " prefix
	in the diagnostic, when !brief.
	* NEWS (Changes in behavior): Mention the diagnostic change.
	Reported by Andreas Hoenen in http://bugs.debian.org/570064.

2010-02-14  Juan Manuel Guerrero  <juan.guerrero@gmx.de>

	avoid compilation failure on systems lacking both fork and vfork
	* src/sdiff.c [!HAVE_WORKING_FORK && !HAVE_WORKING_VFORK] (main):
	Pass the right number of arguments to shell_quote_copy.
	* src/util.c [!HAVE_WORKING_FORK && !HAVE_WORKING_VFORK] (begin_output):
	Likewise.

2010-02-11  Jim Meyering  <meyering@redhat.com>

	post-release administrivia
	* NEWS: Add header line for next release.
	* .prev-version: Record previous version.
	* cfg.mk (old_NEWS_hash): Auto-update.

	version 2.9
	* NEWS: Record release date.

	doc: document the release procedure
	* README-release: New file.

2010-02-10  Jim Meyering  <meyering@redhat.com>

	maint: change use of "|" to more maintainable "||" (no semantic change)
	* src/analyze.c (diff_2_files): Using the "||" operator happens to
	be equivalent to using "|" in this case.  It is also clearer and
	less prone to inadvertent bug introduction, in case the variable,
	"changes" were ever to take on a value not in {0,1}.
	Patch by Tim Waugh, via Mike Frysinger.

	portability: avoid "diff - ..." failure at least on *BSD and Solaris
	The new "stdin" test was failing on many types of systems.
	* src/diff.c (compare_files): Guard use of xfreopen (NULL, "rb", ...
	also with O_BINARY, so as to avoid this unnecessary call on
	systems where it's not needed (on some it fails with "Bad address".

2010-02-09  Jim Meyering  <meyering@redhat.com>

	tests: honor VERBOSE
	* tests/basic: Enable "set -x" if $VERBOSE.
	* tests/help-version: Likewise.
	* tests/label-vs-func: Likewise.
	* tests/stdin: Likewise.

2010-02-04  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

	sync with gnulib
	* gl/lib/regcomp.c.diff: Adjust to apply to the latest in gnulib.
	* gnulib: Update submodule to latest.

2010-02-04  Jim Meyering  <meyering@redhat.com>

	build: do not override gnulib-provided AM_CFLAGS options
	Avoid a warning from automake:
	lib/Makefile.am:23: AM_CFLAGS multiply defined in condition TRUE ...
	lib/gnulib.mk:30: ... `AM_CFLAGS' previously defined here
	lib/Makefile.am:18:   `lib/gnulib.mk' included from here

	* lib/Makefile.am (AM_CFLAGS): Append $(WARN_CFLAGS) and
	$(WERROR_CFLAGS), i.e., use "+=", not "=".
	This was introduced via 2009-12-17 commit e58efa5b
	"build: enable warnings and -Werror.",
	but fortunately is not a bug, because the definition
	it would have overridden was always empty.

2010-01-17  Jim Meyering  <meyering@redhat.com>

	maint: add to .gitignore
	* .gitignore: Ignore more.

2010-01-15  Jim Meyering  <meyering@redhat.com>

	doc: add to TODO
	* TODO: Add an item, suggested by Dan Jacobson.

2010-01-13  Jim Meyering  <meyering@redhat.com>

	tests: ensure that an argument of "-" is treated as standard input
	* tests/stdin: New test.
	* tests/Makefile.am (TESTS): Add it.

2010-01-10  Jim Meyering  <meyering@redhat.com>

	tests: now "make distcheck" runs more tests, incl. syntax-check
	* cfg.mk: Include dist-check.mk, from coreutils.
	* Makefile.am (distcheck-hook): Define rule, to hook to...
	* dist-check.mk: New file.

2010-01-09  Jim Meyering  <meyering@redhat.com>

	build: update gnulib to latest, for fixed syntax-check rule

	maint: record updated NEWS hash
	* cfg.mk (old_NEWS_hash): Update to account for GFDL change.

	build: update gnulib submodule to latest

	tests: add a test of basic functionality
	* tests/basic: Start adding tests.
	* tests/Makefile.am (TESTS): Add it.

	maint: udpate GFDL license to 1.3
	* doc/diff.texi: Update to use GFDL version 1.3.

2010-01-04  Eric Blake  <ebb9@byu.net>

	build: allow compilation on cygwin
	* src/Makefile.am (cmp_LDADD): Move LIBICONV...
	(LDADD): ...into global flags, since all programs need it.

2010-01-03  Jim Meyering  <meyering@redhat.com>

	maint: record update-copyright options for this package
	* cfg.mk: Next time, just run "make update-copyright".

	tests: prepend ../src, not "." to PATH
	* tests/help-version: Correct PATH.

2010-01-01  Jim Meyering  <meyering@redhat.com>

	maint: update all FSF copyright year lists to include 2010
	Use this command:
	git ls-files |grep -vE '^(\..*|COPYING|gnulib)$' |xargs \
	env UPDATE_COPYRIGHT_USE_INTERVALS=1 build-aux/update-copyright

2009-12-31  Jim Meyering  <meyering@redhat.com>

	maint: newer gnulib; don't hard-code my GPG key ID
	* cfg.mk (gpg_key_ID): Remove definition, now that maint.mk automates it.
	* gnulib: Update to latest.

	tests: exercise diff -p's function-name matching
	* tests/label-vs-func: New file.
	* tests/Makefile.am (TESTS): Add label-vs-func.
	Reported by Simon Arlott <simon@fire.lp0.eu>
	http://article.gmane.org/gmane.linux.kernel.janitors/14260

	tests: use gnulib's init.sh
	* tests/Makefile.am (EXTRA_DIST): Add init.sh.
	Remove test-lib.sh.
	* tests/init.sh: New file.
	* tests/test-lib.sh: Remove file.
	* tests/help-version: Use init.sh, not test-lib.sh.

2009-11-28  Jim Meyering  <meyering@redhat.com>

	maint: don't let trailing spaces in diffs perturb make syntax-check
	* .x-sc_space_tab: New file.

2009-11-22  Jim Meyering  <meyering@redhat.com>

	build: enable warnings and -Werror.
	* src/Makefile.am (AM_CFLAGS): Enable warnings and -Werror.
	Set to this: $(WARN_CFLAGS) $(WERROR_CFLAGS)
	* lib/Makefile.am (AM_CFLAGS): Similarly, but use this:
	$(GNULIB_WARN_CFLAGS) $(WERROR_CFLAGS)
	* configure.ac (GNULIB_WARN_CFLAGS): Don't turn off -Wuninitialized.

	build: avoid a warning from gnulib's sh-quote.c
	* gl/lib/sh-quote.c.diff: New file, to avoid a warning.

	maint: avoid warnings via patched versions of gnulib's regex functions
	* gl/lib/regcomp.c.diff: New file.
	* gl/lib/regex_internal.c.diff: Likewise.
	* gl/lib/regex_internal.h.diff: Likewise.
	* gl/lib/regexec.c.diff: Likewise.

	build: update gnulib submodule to latest

2009-11-20  Eric Blake  <ebb9@byu.net>

	build: ignore more files
	* .gitignore: Add config.cache, *.exe.

2009-11-20  Eric Blake  <ebb9@byu.net>

	build: fix test run on cygwin
	This, plus a gnulib update for xalloc-die-tests, are necessary
	for make check to pass on cygwin.

	* tests/Makefile.am (built_programs): Ignore $(EXEEXT).
	* src/Makefile.am (paths.h): Add missing dependency.

2009-11-20  Jim Meyering  <meyering@redhat.com>

	maint: remove vestiges of nanosleep
	* src/Makefile.am (LDADD): Remove $(LIB_NANOSLEEP), now
	that we no longer use the nanosleep module.
	Spotted by Eric Blake.

	maint: don't pull in gnulib's nanosleep unnecessarily
	* bootstrap.conf (gnulib_modules): Remove nanosleep.  Not needed.
	Spotted by Eric Blake.

	maint: cfg.mk: remove factored-out ftp host/dir definitions
	* cfg.mk (gnu_ftp_host-alpha, gnu_ftp_host-beta gnu_ftp_host-stable):
	(gnu_rel_host, url_dir_list): Remove definitions.  The defaults,
	now provided by maint.mk, are the same.
	* gnulib: Update for latest, including those maint.mk additions.

	build: link with now-required libraries
	* src/Makefile.am (LDADD): Add gnulib-required libraries.
	(cmp_LDADD): Add $(LIBICONV), for cmp's use of proper_name_utf8.

	maint: lib/xfreopen.c contains translatable strings
	* po/POTFILES.in: Add lib/xfreopen.c.

	maint: remove hard-coded macro definitions provided by intprops.h
	* lib/cmpbuf.c: Include "intprops.h" rather than open-coding macros
	like TYPE_SIGNED and TYPE_MINIMUM.

	maint: add gnulib's announce-gen module
	* bootstrap.conf (gnulib_modules): Add announce-gen

	build: suppress warnings about bindtextdomain and textdomain
	* src/system.h (bindtextdomain, textdomain) [!ENABLE_NLS]: Define away.

	build: use more gnulib modules
	* bootstrap.conf (gnulib_modules): Add mktime, nanosleep, strptime
	and timegm.

	use xfreopen rather than freopen
	* src/cmp.c: Include "xfreopen.h".
	Use xfreopen in place of freopen.
	* src/diff.c Likewise, and...
	(main): Set exit_failure to EXIT_TROUBLE, rather than to 2.
	* src/diff3.c: Likewise.
	* bootstrap.conf (gnulib_modules): Add xfreopen.

	build: enable many warnings
	* configure.ac: Add support for --enable-gcc-warnings.
	* bootstrap.conf (gnulib_modules): Add manywarnings.
	* Makefile.am (AM_CFLAGS): Add $(WARN_CFLAGS) $(WERROR_CFLAGS)

	build: update gnulib submodule to latest

	maint: add an assertion to suppress clang-detected warning
	The clang static analyzer reported that a NULL parent could be
	dereferenced.  However, that cannot happen, because for all callers,
	the parameter, parent, is always non-NULL at that point.
	* src/diff.c: Include <assert.h>.
	Assert that parent is not NULL.

	maint: remove dead assignment from diff3.c
	* src/diff3.c (make_3way_diff): Remove dead assignment.

2009-11-17  Jim Meyering  <meyering@redhat.com>

	build: update gnulib submodule to latest

	maint: hide build commands behind $(AM_V_GEN)
	* src/Makefile.am (paths.h): Use $(AM_V_GEN), and split a long line.
	* man/Makefile.am ($(dist_man1_MANS)): Use $(AM_V_GEN) here, too.

2009-11-16  Jim Meyering  <meyering@redhat.com>

	build: let automake generate better man-installation rules
	* man/Makefile.am (dist_man1_MANS): Rename from dist_man_MANS,
	to enable better automake-generated installation rules.

	admin: ignore all of gnulib-tests
	* .gitignore: Add gnulib-tests

2009-11-16  Eric Blake  <ebb9@byu.net>

	build: avoid link failure when libsigsegv is used
	* src/Makefile.am (LDADD): Link against LIBSIGSEGV.

2009-11-16  Jim Meyering  <meyering@redhat.com>

	maint: define/use PROGRAM_NAME and AUTHORS; use propername module
	* bootstrap.conf (gnulib_modules): Add propername.
	* src/cmp.c (PROGRAM_NAME, AUTHORS): Define.
	(main): Use them in use of version_etc.
	* src/diff.c (PROGRAM_NAME, AUTHORS, main): Likewise.
	* src/diff3.c (PROGRAM_NAME, AUTHORS, main): Likewise.
	* src/sdiff.c (PROGRAM_NAME, AUTHORS, main): Likewise.
	* src/system.h: Include "propername.h".

	maint: no longer define *_FILENO constants
	* src/system.h (STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO):
	Remove definitions.  Now guaranteed by gnulib.

	maint: bug-diffutils@gnu.org is the new bug-reporting address
	* configure.ac (AC_INIT): Use bug-diffutils@..., not bug-gnu-utils
	as the bug-reporting address.
	* NEWS (Administrivia): Mention this.
	* src/cmp.c (usage): Remove hard-coded address.
	Instead, use gnulib's emit_bug_reporting_address function.
	* src/diff.c (usage, option_help_msgid): Likewise.
	* src/diff3.c (usage): Likewise.
	* src/sdiff.c (usage): Likewise.

	sdiff, diff3: exec diff, not $(bindir)/diff
	* src/Makefile.am (paths.h): Emit a definition of DEFAULT_DIFF_PROGRAM
	that is simply "diff" (or whatever $(transform) would convert that to,
	e.g., "gdiff").  This makes it so that tests can work without first
	installing diff, and so that the binaries do not hard-code $(prefix).
	* NEWS (Changes in behavior): Mention this.

2009-11-14  Jim Meyering  <meyering@redhat.com>

	tests: add the first script; hook up gnulib-tests
	* configure.ac (AC_CONFIG_FILES): Add tests/Makefile and
	gnulib-tests/Makefile.
	* tests/help-version: New file, from coreutils.
	* tests/test-lib.sh: Likewise.
	* tests/Makefile.am: New file, from gzip.
	* Makefile.am (SUBDIRS): Add tests and gnulib-tests.
	* tests/t-local.sh: New, empty(for now) file.

2009-11-13  Jim Meyering  <meyering@redhat.com>

	build: require gettext-0.17
	* configure.ac: Require gettext-0.17; it was released two years ago.

	build: correct gettext configure-time support
	* configure.ac: Use AM_GNU_GETTEXT([external], [need-ngettext]),
	rather than AM_GNU_GETTEXT([external], [need-formatstring-macros]).
	Reported by Martin Jacobs in
	http://thread.gmane.org/gmane.comp.parsers.bison.bugs/3181

2009-11-12  Jim Meyering  <meyering@redhat.com>

	build: generalize autoheader check
	* bootstrap: Look for AC_CONFIG_HEADER as well as AC_CONFIG_HEADERS.

2009-11-11  Jim Meyering  <meyering@redhat.com>

	maint: use a git submodule for gnulib
	* .gitmodules: New file, to track gnulib.
	* gnulib: New file, created by running this:
	git submodule add git://git.sv.gnu.org/gnulib.git gnulib

	maint: tell git what it can ignore
	* .gitignore: Ignore generated files.