==================
   TODO: xxdiff
==================

.. contents::
..
    1  Next Release
      1.1  Priorities
      1.2  Qt4
    2  Less Urgent, but do it soon too
    3  Look at ``wiggle`` integration, it seems like a great idea
    4  Goals for 4.0 stable release:
    5  Promo
    6  Other


Next Release
============

Priorities
----------

- xxdiff: Make xxdiff recursive able to list all the files when a
  directory is only on one side. Walk and enumerate the files of an
  inserted or deleted directory.

- xxdiff: Fix geometry window sizing problem.

- xxdiff: Convert it to port to Qt4 and support unicode

  - Windows port, use the patch from Trevor Harmon
  - MAC port
  - Patch output support?



Qt4
---

- Bug with saving with ignored patterns: Which side gets selected?

      Ah I see.
      The problem is a definitional one.
      When you say "Save as..", it is not clear what to do with the ignored regions, xxdiff should warn about that.
      It's indeed a problem...

      The issue is that xxdiff does not output sed commands... it selects the regions and saves the results directly.

      You should probably not use the ignore switch with save... I never considered that case.
      BTW, "Save As Right" does not mean anything about selecting text from the file on the right, it is the same as "Save As"
      and selecting the filename of the file on the right.

      THanks for the bug report, I'll add it to the TODO list.

      cheers,

      Lee Gramling wrote:
      > > Martin,
      > > Thanks for your quick response, I am sure its just my expectations that
      > > are wrong but here is better description:
      > > 
      > > Run the following command on the files listed below:
      > >  xxdiff d2.iv d1.iv -A "-I position.*"
      > > 
      > > xxdiff when show the following differences:
      > > d2.iv                                     d1.iv
      > > position 50 50 200                position 50 50 280     #these are
      > > ignored and not highlighted
      > > 
      > > angle 3.19                            angle 1.57
      > > 
      > >  Text3 {
      > >             string  =
      > >                  GlobalField {
      > >                      type    "SFTime"
      > >                      realTime
      > >                  }
      > >                  . realTime
      > >          }
      > > 
      > > Select the right angle 1.57
      > > and the left Text3 block
      > > 
      > > Then do a File->Save as right
      > > File->Redo diff
      > > 
      > > Now the files looks like this:
      > > d2.iv                                     d1.iv
      > > position 50 50 200                position 50 50 200     #d1.iv has the
      > > wrong value for position
      > > 
      > > angle 3.19                            angle 1.57
      > > 
      > >  Text3 {                                    Text3 {
      > > string  =                                   string =
      > > GlobalField {                            GlobalField {
      > > type    "SFTime"                       type    "SFTime"
      > > realTime                                   realTime
      > >  }                                               }
      > >  . realTime                                .realTime
      > >   }                                              }
      > > 
      > > The ignored position line has been copied to the right file (I would not
      > > expect this).
      > > The selected right angle 1.57 is correct and the left selected Text3
      > > line has been added as expected.
      > > 
      > > I guess what I expect is more like what would happen if you ran diff
      > > with the ignore
      > >  diff d2.iv d1.iv "-I position.*"
      > > 15c15
      > > <             angle   3.19
      > > ---
      >> >>             angle   1.57
      > > 25,32d24
      > > <          Text3 {
      > > <             string  =
      > > <                 GlobalField {
      > > <                     type    "SFTime"
      > > <                     realTime
      > > <                 }
      > > <                 . realTime
      > > <         }
      > > 
      > > The ignored lines do not get output as sed commands.
      > > 
      > > Thanks for your time.
      > > 
      > > Lee
      > > 
      > > 
      > >  d1.iv:
      > >  Separator {
      > >         PerspectiveCamera {
      > >             position 50 50 280
      > >         }
      > >         Text3 {
      > >             string  "undefined" =
      > >                 GlobalField {
      > >                     type    "SFTime"
      > >                     realTime
      > >                 }
      > >                 . realTime
      > >         }
      > >         RotationXYZ {
      > >             axis    Z
      > >             angle   1.57
      > >         }
      > >         Text3 {
      > >             string  =
      > >                 GlobalField {
      > >                     type    "SFTime"
      > >                     realTime
      > >                 }
      > >                 . realTime
      > >         }
      > >     }
      > > 
      > >  d2.iv
      > >  Separator {
      > >         PerspectiveCamera {
      > >             position 50 50 200
      > >         }
      > >         Text3 {
      > >             string  "undefined" =
      > >                 GlobalField {
      > >                     type    "SFTime"
      > >                     realTime
      > >                 }
      > >                 . realTime
      > >         }
      > >         RotationXYZ {
      > >             axis    Z
      > >             angle   3.19
      > >         }
      > >         Text3 {
      > >             string  =
      > >                 GlobalField {
      > >                     type    "SFTime"
      > >                     realTime
      > >                 }
      > >                 . realTime
      > >         }
      > >          Text3 {
      > >             string  =
      > >                 GlobalField {
      > >                     type    "SFTime"
      > >                     realTime
      > >                 }
      > >                 . realTime
      > >         }
      > >     }
      > > 
      > > 
      > > 
      > > On Nov 19, 2007 10:04 AM, Martin Blais <blais@furius.ca
      > > <mailto:blais@furius.ca>> wrote:
      > > 
      > >     Hi Lee
      > >     Can you send a step-by-step description to reproduce the problem?
      > >     I don't quite understand your explanation below.
      > >     (I would highly doubt a bug in that part of xxdiff at this point.)
      > >     thx


- Apply Trevor Harmon's patch for the port to Qt4.

- Finish half-started save-to-patch feature:

  * Add an option to the xxdiff GUI to invert the selections, or to save the
    negative of the selections to a file.  Using this, we could split a file in
    half.  This should not be available in 3-way diffs mode.



- Fix this bug::

    Grant McDorman <grmcdorman@gmail.com>:

      I've got xxdiff running - with patches on Win32 with Qt Free 4.2.0 (and
      mingw). Fixes were required, not suprisingly.

      There was also what appears to be a real bug that showed up. In
      hordiffimpl.cpp, there's a loop that starts like this:

            while ( x > -1 && y > -1 ) {
      #ifdef XX_LOCAL_HDIFF_DEBUG
               cerr << x << " " << y << " = " << htable[ x + y*tlen0 ] << endl;
      #endif

               if (
                  ( htable[ x + y*tlen0 ] == ( htable[ x-1 + (y-1)*tlen0 ] + 1 ) /*||
                    htable[ x + y*tlen0 ] == htable[ x-1 + (y-1)*tlen0 ]*/ ) &&
                  ctext0[x] == ctext1[y]

      However, the problem is if x or y becomes 0, then one can have a negative
      subscript on the second htable index. This can cause crashes. I fixed by
      making it '> 0' instead of '> -1'.

      There were also layout problems, such as the headers (filename/line number
      way too bing); it's not clear to me if this is a Qt4 problem or a Win32
      problem.

      There are still a few minor problems: the file names start up blank (if
      one does 'replace file' from the file menu, it's labelled correctly); and
      the colour swatches in the display options dialog, Colors tab, don't
      change colour at all. I haven't tracked those down yet.

      I can send you the patch on request - or submit to SF.


Less Urgent, but do it soon too
===============================

* Add a '-w' option to invoke.py (!?), to ignore whitespace changes easily.

* When the comments file has not changed, warn the user that he did not appear
  to have saved the file.

* It would be awesome if select.py had an option to select by file-type
  (e.g. running “file”).  Open a child running a “file” command and feed it the
  filenames one-by-one rather than starting a new one everytime.

* Look at fixing the bugs in xxdiff/test/bugs

* For MAC OSX: if there are no files specified, invoke a special double- file
  dialog chooser to graphically select which files to diff.

* xx-svn-diff: Comments file: To add new files to the comments file:

  a) Check if at least one line of the comments file is the same as any line of
     the status OR if the file is empty

  b) if so, add all the status lines tha tdiffer at thte end of the comments
     file (with an empty line in between)

  c) otherwise we do not append the new statii lines

* Bug: toggling "Format clipboard text" at runtime does not seem to have an
  effect.

* Fix [1200496] Diff Errors reported with certain text files

* xx-svn-diff: Implement fetching any two revisions and displaying the filelist
  and the diffs graphically for those changes.

* See open bug [1174957] Odd behavior when "-O" and "-E" used together:  When
  --exit-if-no-conflicts and --merged-filename are specified together, and there
  are no conflicts, output the result file to the merged filename.

* There is a slight rendering bug with my current font (see png file under /bugs)

* Define a clearer list of verbosity levels that is consistent across all the
  scripts and change the levels.

* Automatically log output to a log file in the backups directory if the backups
  are enabled, that would rock.

--------------------------------------------------------------------------------
(Scripts)

* When xxdiff is invoked with --decision and -D, which answer should result?
  Right now we output NODECISION, but perhaps ACCEPT would be more appropriate?
  I'm not sure.

* Write an asynchronous background loop in xformloop for slow processes, where a
  number of diffs could accumulate in the background and be ready to diff while
  whatever is being done to produce the diffs keeps running.  Grab this from my
  good old exp preview.  Put this in ``lib/python/xxdiff/async.py``

  (Note: this goes hand-in-hand with the diff'ing of arbitraty SVN revisions, as
  we will have to fetch files from the network and this might be slow.
  Implement both of these features at the same time.)

* xx-svn-diff: When the parent process gets killed, make sure to kill the
  editor as well, otherwise it can be really annoying because this leaves swap
  files around if we restart manually killing the editing window (which can
  happen if you leave it in the background).

* Provide a way to invoke xxdiff with alternate diff programs.

  - Using this code, provide code to create alternate diff programs that compare
    pairs of things, with or without subdiffs, by outputting POSIX diff output.


* xx-rename: With respect to case sensitivity, supports the smart
  replacement behaviour that is present in GNU emacs.

* Implement a better side-by-side diff that includes line numbers and context.
  The current side-by-side diff sucks.  One of the things that could be done
  easily is reuse diff --side-by-side without compressing, adding the line
  numbers by hand, and then compressing by hand too.

  - Add an option to generate normal diffs rather than side-by-side.

* xx-patch: Finish It! 

  * You have to deal with 'delete' and 'add' cases.

  * Q: what do we do when patch fails?  How do we treat it?
    must read the output messages of patch and warn the user.

* xx-svn-diff: TODO

  * --launcher: Create simple PyQt or CURSES GUI for listing files from ``svn
    status``, on which you can click to view the diffs.

  * Implement including differences from the ancestor file with 3-way diffs.

  * Implement viewing differences between any two revision in the repository.

  * Wouldn't it be nice to have a decision mode here?  Maybe, maybe not.  You
    can save as merged if desired, the merged filename is set to the output
    filename.

* Fix these old subprocesses by using the subprocess module::

   banane:~/p/.../python/xxdiff$ igrep os.popen .
   ./scripts/encrypted.py:        fin, fout = os.popen2(decodecmd % m, 'w')
   ./scripts/encrypted.py:        fin, fout = os.popen2(cmd, 'w')
   ./scripts/cvsdiff.py:        cin, cout = os.popen2(
   ./scripts/patch.py:        cin, cout = os.popen2(cmd, 'rw')

* Implement --single-right: we should be able to display single files on either
  side.  You should fix xx-match after that, so that it passes the correct
  options to xxdiff.

* Consider putting a check for binary files in xxdiff.invoke.* and raise a
  RuntimeError if the files aren't text.

* xx-rename: We should able to read renames from a file, two names by line, or
  something similar.

--------------------------------------------------------------------------------

* Idea: we could modify xxdiff so that when we reload, we could output RELOAD
  and that could mean for the client to redo some task in the background, then
  let xxdiff know to reload after that.  This would allow xxdiff to communicate
  with the parent process.  This should actually be part of a larger protocol
  for client to communicate with xxdiff and vice-versa.  This is a cool idea,
  but a lot of work for very little benefit.

* Check if this bug is gone::

    I set up xxdiff-subversion on my workstation following web page at
    http://xxdiff.sourceforge.net/local/doc/xxdiff-subversion.html. It works
    just fine for svn diff command. But for svn up, if there is a conflict,
    xxdiff will pop up showing three way difference. When I close xxdiff
    window, I found my working copy of that conflicting file became blank!
    So I lost all my changes in that file!

    My current solution is not to set diff3-cmd in ~/.subversion/config file.

    --Long

    PS: I am using FreeBSD.
    pkg_info -Ix xxdiff
    xxdiff-3.0.3        QT interface to view/merge differences between 2 or
    3 files
    pkg_info -Ix subversion
    subversion-1.3.0_3  Version control system


* From Michalis Giannakidis, mgiann@beta-cae.gr

  Do this:

    What, here in our company, find useful about cvsxxdiff is:
    o) cvsxxdiff is one file. No python module directory or initialization is
    requierd.
    o) Do a 'cvs up; cvsxxdiff' before commit to see all the local changes we have
    made.
    o) Do 'cvs up; cvsxxdiff -b 1 file.c' to see the last chages that were made on
    a file by a colleague.
    o) We often need to track bugs in our code. This means going back to previous
    revisions, thus doing ex: 'cvsxxdiff -b 1 -b 2 file.c' to compare the
    previous with the 2nd previous revision. (similar with cvsxxdiff -r 1.1 -r
    1.2 file.c)
    o) The utility prints  in the standard output the logs between revisions i
    and j ( ex: cvsxxdif -b i -b j file.c)

    One script to do it all.





Look at ``wiggle`` integration, it seems like a great idea
==========================================================

  From: Ken.MacLeod@radisys.com <Ken.MacLeod@radisys.com>	
  To: blais@furius.ca
  Date: Aug 10, 2006 9:17 AM
  Subject: xxdiff: patch wiggling
  Reply | Reply to all | Forward | Print | Add sender to Contacts list | Delete this message | Report phishing | Show original | Message text garbled?
  A long while back in 2003, you wrote,
  http://www.uwsg.iu.edu/hypermail/linux/kernel/0203.2/1177.html

  Not long after, Niel Brown announced 'wiggle',
  http://www.uwsg.iu.edu/hypermail/linux/kernel/0305.2/0762.html

  Niel mentions one of the shortcomings in wiggle is that you can't "see"
  what it's done or will do.  Here's where xxdiff can pick that up.  These
  are just thoughts off the top of my head, sorry I won't have patches
  forthcoming with implementation :-/

  I'd like to see the entire patch in the left pane, probably in the format
  used by gitweb[1] or gitk[2, screenshot in 3].

  Selecting a patch hunk on the left brings up the corresponding source in
  the right pane, with the "new" changes highlighted (with horizontal diff,
  natch :-).  The old changes are not necessary, though a three-pane view
  could have them on the left.

  The hunks in the patch pane should be marked according to their merge
  status, ie. green for success, yellow for offset, orange for fuzz, and red
  for failed.  A "check mark" would be nice for hunks that have been
  confirmed and/or fixed up.

  If a patch fails because the file cannot be found due to a rename, the
  merge path should be editable.  (Auto-rename is possible if both trees are
  available.)

  Wiggle's algorithm is good for finding better matches.

  Changes should not be applied until selected from a menu.

  After wiggling, the patch should be saved so that it can be emailed.  The
  updated patch should now cleanly apply against the tree it was wiggled to
  (ie. counts and offsets corrected, a la recountdiff).

  OK, that's all I can brain dump for now.  Of course, it wasn't until after
  writing it that I see xx-patch, so, take whatever good bits seem to make
  sense :-)

   -- Ken

  [1]
  http://www.kernel.org/git/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=log
  [2] http://ozlabs.org/~paulus/gitk/
  [3] http://lwn.net/Articles/140350/



--------------------------------------------------------------------------------

- Install xxdiff on windows, when Qt4 non-commercial comes out

- try beyondcompare::

   Si jamais tu veux retravailler sur xxdiff, je viens de trouver le canif
   suisse des diffs graphiques, tu manqueras pas d'id\x{00E9}es pour xxdiff
   avec \x{00E7}a... Absolument incroyable (mais c'est un produit
   commercial). \x{00C7}a s'appelle "Beyond Compare" de Scooter Software. Le
   genre de programme qui te fait dire "enfin sti". \x{00C7}a compare aussi des
   r\x{00E9}pertoires (r\x{00E9}cursivement itou, avec des diffs par fichier),
   et c'est aussi incroyablement facile de faire un merge. Vraiment
   g\x{00E9}nial..
   http://www.scootersoftware.com/



* Bugs with horizontal diffs:

    However, I do have a suggestion. Your code does not
    seem to be using a logic such as the Ratcliff/Obershelp
    pattern recognition algorithm, which is adopted by some
    other common graphical diff tools. Using such a logic,
    they search for the longest common substring between
    two strings. The match is then used as an archor,
    around which they would recursively do the same for the
    left and right remaining pieces.


New feature, ignore regexp patterns::

  Bonjour Martin,
  Comme convenu voici le  feature  que je trouvais utile dans Examdiff Pro :
  - Regular Expression support dans le champs Ignore.
  Exemple :
              Faire une comparaison de 2 fichiers contenant des UID que je ne veux pas considérer comme différent lors de la comparaison.
  Contexte :
              j'avais a comparer des fichiers generes par un generateur de code java.  les fichiers contenait des code pockets du genre:
  // BEGIN Code pocket ID : XXXX-XXXX-XXXX-XXXX
  // Some code to be preserved when regenarating
  // END Code pocket ID : XXXX-XXXX-XXXX-XXXX

  Je pouvais avec Examdiff Pro exclure de ma comparaison les "Code pockets" au
  complet (pas seulement les tag mais aussi le contenu du code pocket avec un
  regular expression.  Voil


* fix bug on tp with 3-way, press S::

    QPixmap: Invalid pixmap parameters
    QPainter::begin: Cannot paint null pixmap
    QPainter::setPen: Will be reset by begin()
    Segmentation fault



* with option --single it would be nice to be able to say that the file should
  be displayed on the right side and not the left, this would be nice for
  directory diffs when clicking on a hunk where there is only a file on the
  right.  Right now the file appears on the left anyway, which just looks wrong.



* Maybe create a new return code for the combination of ``--decision`` and
  ``-D``::

    int XxApp::exec()
    {
       if ( _dontShow ) {
          // If we asked for a decision, at least output something.
          // FIXME: maybe this should become NODIFF?
          if ( _cmdline._forceDecision == true ) {
             std::cout << "NODECISION" << std::endl;



* prepare to build with qmake



* add the horizontal marker to the options dialog as well.


* xxdiff test/tabs/w2a test/tabs/w2b::

        while ( true ) {
     #ifndef XX_INTERNAL_DIFFS
           // FIXME here we should change the code so that reading a line
           includes // the carriage return characters within the line.  This
           results in // harmless but nonetheless annoying empty diff error
           messages.
           QString line = outputs.readLine();


* Known problem:

  - set tab width to 0
  - diff files which have tabs and spaces but other characters the same
  - set hordiff threshold low enough

  We get minimum hordiff width to 1 with this combination.
  I think we would need to recompute the diffs.








.. end

(Horizontal Diffs)

- post-process, idea from Derrick Moser, slide to the left until a word boundary
  is met on either side or is impossible


Goals for 4.0 stable release:
=============================

   * Finish scrollbars resizing for paned merged view.
   * Improve error recovery in rcfile parsing.


Promo
=====

- promotion on xxdiff webpage before release:  ask ev and gd for a quote, how
  many developers, etc.

- send email to GnuPG mailing-list about xx-encrypted script





Other
=====

* write a script that can preview ``xdelta patch``.

* add a command to keep spit out the output of diff in a window (useful for
  debugging as well)

* add an option to edit the file from the popup menu, it's more direct like
  that than using the File menu.

  - same for Save As...
  - also add a "save as and edit" option.


* From qt-3.2::

    QPainter's complex drawText() function has been highly
    optimized. Despite its support for complex unicode scripts, it now
    performs better than its less unicode-capable counterpart in Qt 2.3.

  So I should port to use that instead.


  * find a way to use the doc.txt docutils format for all documentation
    (you can generate PDF with docutils and pdflatex already).

  * xxdiff -D that succeed leaves a mutex destroy failure message... find the bug!


   2) make able to see if there are any changes at all, to do this, we'll
      compare all chars of the buffers by hand, if there is ANY differences that
      it is different;  check size of buffers first


  * cursor is not following scrolling anymore, FIX THIS this is annoying when
    using the keyboard


  * change config to use XML instead, add 'xxdiff --dtd' to obtain dtd.

  * change key binding for variable text selection

  * check out bug from (wesleysmith)

If I select the line from the first column and then
run "Save as left", I get a dialog that says "The
selections are all on this file. Save anyway?". If I
choose either the middle or right column and run "Save
as left", then I don't see this message. I also see this
message if I select the middle column and then
run "Save as middle". It seems to me that this
message doesn't really apply to the unmerge3 case,
and should be disabled.

Also, in the File menu, "Save as left" and "Save as
middle" are activated, but "Save as right" is grayed out.
That's odd because all three columns are the same file.
Seems like they should all be available, or maybe only
one, with the name changed to "Save".

A similar problem is seen with the "Edit ..." menu items
on the File menu.



2 prorities for review:

   1) make able to make comments rapidly

   2) make able to see if there are any changes at all (turn off all ignore options at once?)
      or perhaps look at the diff output

   * quote output of clipboard header format \n's to be able to read back the
     xxdiffrc file.


   * create separate popup menus for different builders instead of ifdef
     technology

   * add "Edit Merged Filename" to resolve conflicts.

   * implement --exclude and --exclude-from for directories, it would be really
     useful for CVS directories

   * implement arbitrary secondary selection, with filename in the clipboard,
     for making easy merge comments, that would print filename, and pasted text

   * Special "File" dialog with display and real filenames, with save as,
     replace and edit buttons.

   * try this: with horizontal diffs, remove two first chars of a line whose
     indentation has changed, the horizontal diff will span from the beginning
     of the line. this is not desired.

   * in 3-way diffs mode, when you ignore one file, you must recompute the
     horizontal diffs between the other two files only!  this would be very
     useful actually.

   * Add Accel.Quit alias for Accel.Exit

   * xxdiff --version now results in the following error msg from Qt 3:
      Mutex destroy failure: Device or resource busy
     fix it. this doesn't seem to have other implications.

(Split swap join improvements)

   * Michael idea: split swap join where the cursor line is located

(Urgent)

   * Update documentation with this version.

   * Make per-hunk display ignore toggleable

//   * ./xxdiff mine util.h app.h Segfaults!!!! fix this??!
// i think i just fixed it already


   * XxText should accept() or ignore() its events.

   * When in unmerge mode, saveAsMerge feature initializes merge file name as 01234567.

   * Add format for filename label as well, useful for making merge comments.

   * Invert logic of "Remove Empty Conditionals", that should be the default.


(Per-hunk Ignore Whitespace)

   * Not sure that the split-swap-join vs. ignore-display behaviour is correct,
     perhaps should become green anyway when split?

   * Maybe we can use the horizontal diffs computation to speed up the per-hunk ws?

   * Implement partial hunk ignore ws, newlines have to match (but you can skip some).



(Ignore Blank Lines)

   * Consider.... should we do something about ignored SAME sides when saving? I
     mean, now we just choose side 0, but perhaps we want to give the user
     control over that?


(Misc)

   * scrolling with the scrollbar doesn't seem to restrict the cursor anymore

   * Some of our display algorithms allow the user to effectively ignore certain
     hunks. If all diff hunks are ignored by our display algorithms, could we
     prevent xxdiff from even showing up at all? And if we do want it to remain
     visible anyway, I think we should somehow put markers indicating at least
     where whitespace changes occur anyway, in the margin or something, just to
     be able to figure out if a file really does has some [whitespace] changes
     or nothing at all.

   * The cursor is not restricted by scrolling using the scrollbars anymore!!!

   * When pasting to the clipboard, turn tabs into spaces, for much better
     results when pasting! remember, the clipboard formatting can otherwise
     change it.

   * Paned view problem, the hash pattern that is drawn is not cleared before it
     is drawn, switch workspaces with paned view and you'll see immediately.


(Colors)

   * There is no SelectedNonly color!


(KDE Port)

   * Trevor:

     By the way, I forgot about a bug in my patch. If you go to Help|User's
     Manual and click on the "GNU website" link at the end, then a web browser
     opens just as it should. But if you click on a local link, such as
     "Introduction", then the web browser again opens, instead of just jumping
     to the point in the text. Help me remember to fix this sometime.




   * ideas from Martin Pool (mbp@samba.org)
    >
    >  - Quick keypresses to switch to next/prev file

    try C-n, C-p, n, p, etc. (see the menus for accelerators)

    or do you mean, a key to open the next/prev file in another diff?
    if so, that's a good idea, i'll put it on the todo list

    >
    >  - Single button to ignore *~, .#*, CVS, and similar garbage.  (The best
    >    way I found was to edit the diff options.)

    i want to do that eventually, that's on the todo list as well






   * fix this problem:

   Hello Martin,

   there's someone reporting that error here:

           http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=141809

   and I do suspect it to be a Qt bug (happens on my box too btw.). I
   searched the web a bit, but couldn't find any solution. Here's the place
   where the error is reported btw.:

           http://www.linux.cz/lists/archive/linux/131195.html

   Does that happen on your box too? Is it a Qt problem?
   *t

   -----------------------------------------------------------------------
        Tomas Pospisek
        sourcepole    -   Linux & Open Source Solutions
        http://sourcepole.com
        Elestastrasse 18,  7310 Bad Ragaz,  Switzerland
        Tel:+41 (81) 330 77 13,  Fax:+41 (81) 330 77 12
   ------------------------------------------------------------------------







   * Cool idea: tooltip when hovering over a hunk should show the diff marker
     text. Or perhaps a popup menu could pop up the textual diff output.


(Build)

   * Try converting build system to use Jam instead of tmake.




   * test recent changes to rendering code to see if it solves the problems with
     qt-3 rendering.


(Automatically-Saving Resources)

   * Some ppl want to have resources saved automatically. Consider an
     implementation.


(Self Debugging and Error Reporting)

   * Print commandline arguments when crashing with an internal error, as well
     as resources state if possible.



(Font Drawing Problem)

   * There is a bug whereby editing the font in the dialog does not work
     properly, the dialog does not show the appropriate font.  This occurs when
     the font is set in .xxdiffrc.  Version: 3.1, the contents of the resources
     file was::

        FontText: "Lucidatypewriter,14,-1,2,50,0,0,0,1,0"
        Accel.Exit: "Alt+Q"

   * Italics fonts sometimes don't draw all that they should be.


(Memory Checking)

   * Run valgrind and mpatrol once again to stabilize.



(Raw diff output)

   * Implement a window to display the raw diff output. Some people may enjoy
     this. kompare (kdiff2) has this.

   * Implement a small widget that would display the current diff output chunk,
     or perhaps put it in the tooltip.


(Misc)

   * When using replace file on a local file, "./" is added before the displayed
     filename, find out why, and eradicate if possible.

   * Convert arrays of string to use a QStringList in many places
     (e.g. cmdline.h)

   * I think we could free the buffers before reloading them on redo diff.

   * set up rsync to update SF automatically from co version at DIRO:
     rsync -Cavz -e ssh  . blais@xxdiff.sourceforge.net:/home/users/b/bl/blais/xxdiff/xxdiff-web



(CVS unmerge conflicts)

   * It would be nice that if you click on the filename labels it wouldn't add
     the "(SOMEFILE)" into the clipboard.


(Printed output)

   * There is currently no generator of xxdiff-like output for printing. See if
     the guts of xxdiff can be reused to implement one, and if so, add an xxdiff
     feature to output to postscript or something.


(Support for Encryption)

   * Add possibility to specify a fd for an alternate input for a second
     file. This way one can almost write a script that runs diff on two memory
     buffers. But how does diff do it then?  Maybe that could be supported with
     linking with the GNU diff code.






Fix warnings reported from Geoff.Kingsmill at compaq compiling with g++-3.x:

>
> -  The following warnings were displayed:-
>
>    text.cpp: In method `virtual void XxText::drawContents(QPainter*)':
>    text.cpp:263: warning: `int py' might be used uninitialized in this
> function
>
>    diffs.cpp: In method `uint XxDiffs::countRemainingUnselected()
> const':
>    diffs.cpp:674: warning: `XxHunk curHunk' might be used uninitialized
> in this
>      function
>    diffs.cpp:675: warning: `XxLine::Type curType' might be used
> uninitialized in
>      this function
>
>    In file included from resParser.cpp:703:
>    resParser.l.c: In function `int XxResParserNS::__yylex(YYSTYPE*)':
>    resParser.l.c:931: warning: label `find_rule' defined but not used
>
>    getopt.c: In function `_getopt_initialize':
>    getopt.c:389: warning: unused parameter `argc'
>    getopt.c:390: warning: unused parameter `argv'




   * When the selections change the merged view horizontal scrollbars should be
     adjusted.

   * Resizing line numbers label leaves white border c**d behind, perhaps it
     should clear the background before drawing.

   * xxdiff still has problems displaying accented chars.

   * Bug: not all control paths in the text rendering engine are setting
     skip. The merged lines counting routine either.

   * Bug in next difference:  use "mine older", then n many times.
     At some point the n command does not bring you to the beginning of a new region.

   * Merged length in lines is incorrectly calculated.

   * The line number labels are not initialized properly on startup.

   * Add cmdline option to show pane-merged view upon startup.

   * Consider using the SUP colors for the empty lines.

   * Scrollbar would be better if it always would be able to show at least a one
     pixel row at the very bottom.

   * Color documentation, shadowed might be "highlighted"... fix it.

   * You need to figure some decent scrolling heuristic for the merged view to
     follow the text views, especially when they are radically different sizes.
     Right now it just follows the cursor.

   * Post-central testing:  test setting tab width, see if horizontal scrollbars
     adjust automatically.

   * Make rpm spec generate documentation automatically.

   * Remove uint, put standard "unsigned int" instead.

   * In merged view, the stippled pattern doesn't scroll horizontally.



(Multiple Horizontal Diffs)

   * Can we actually do something more about 3-way horizontal diffs?
     Compute the 2-way and then merge results?

   * We could remove empty horizontal regions from horizontal diffs?  They don't
     hurt but we could draw more efficiently without them if we don't use them.

   * Perhaps draw a little dent on the side where an insertion/deletion occured.
     With an option.

   * Perhaps group all the horizontal diffs display options together.

   * > Allen Barnett wrote:
     > >
     > > On Thursday 08 November 2001 12:25 pm, you wrote:
     > > > Allen Barnett wrote:
     > > > > One feature which would be helpful to me would be the presence of a
     > > > > 'numerical fuzz' option in the horizontal difference display. If  a line
     > > > > contains a floating point number, but whose numerical difference is below
     > > > > a certain tolerance, it would not be marked as a file difference. For
     > > > > example:
     > > > >
     > > > > 1.2345678E-01  |  1.2345679E-01
     > > > >
     > > > > would not be flagged if the fuzz value is "<10^-6". (Can you tell I do a
     > > > > lot of FORTRAN programming?)
     > > >
     > > > what if this was only implemented for the beginning of the horizontal
     > > > difference?  would that be good enough?
     > >
     > > Typically, my output looks like line after line of:
     > >
     > > 0.182827585 0.140213637 0.113408089 0.140213637 0.106706702 0.0859152186
     > >
     > > One or more of these numbers on a line may differ between runs of the code.
     > > Further reflection on my part suggests that you'd have to parse the line to
     > > find the numbers. Perhaps this isn't really a practical idea after all?
     >
     > I was discussing ideas over lunch with colleagues: soon i'll implement the
     > string edit lcs algorithm for computing multiple horizontal diffs.  one idea
     > that came out is that I could carry this out on a per-token instead of a
     > per-character basis.  The token splitting I'll implement is arbitrary, but I
     > will implement it based on words (where capital letters inside a word splits
     > it).  The whitespace you show above would split your numbers into different
     > tokens.
     >
     > This means that if I apply a "numerical ignore" on the respective horizontal
     > diff hunks of a line it would do exactly what you want, assuming that the words
     > (i.e. numbers) are separated by whitespace.  The numerical comparison will be an
     > option that you can configure in your resources.

(Bugs)

   * In resources::setQuality... setOneOfInCommand, does it remove the options
     that are present if the one to set is empty?

   * Once xxdiff is up, if you change the options for the diff command and give
     it options that make it fail, no error message is printed, no dialog,
     nothing, it just goes empty.

   * Figure out why when a char isn't read by lex/yacc it is printed on stdout,
     and fix that, it's annoying and stupid

   * Redo diff clears selections!  can we do something about it?


(Improve Directory Diffs)

> *  Improve the comparison options for directories. Files and Dirs
>    should be selectively comparable for time, mode, owner,group,
>    and raw and filterd data.
>    I could write the backend of this part, if you like to include
>    this ability, but I can't write the front end (gui) part.


   * Make xxdiff able to go to the parent directories

     While comapring two directory trees I noticed one can
     always go up one level (towards the leafe nodes)
     through the GUI, but not down or 'back'.

    Suggestion:
    Add a new button to the toolbar [arrow-pointing-upwards],
    which stripps the last level of the current path on both sides
    and reads those directories.

    Beware of [up] + / as path :-).
    Thank you,
    Volker Apelt


(Misc)

   * Change file builders to use QCString internally.

   * Optimize parsing the diff outputs, this big series of if-else is
     inefficient, diff2 and diff3 both for files

   * Check out if we can make use of the QApplication useGUI parameter instead
     of not creating the QApplication at all... does it try to open the display
     when set to false?

   * Put all the resources text as what's this in the options dialog

   * Bug: for certain fonts, the text is not drawn completely without the
     fillrect... a line shows up under the text... fix this.
     (In the worst case, detect and fill by hand.)

   * bug: ^L's do not get rendered correctly?...

   * --titlein does not fail when no file is given in stdin.
     This is harmless but perhaps it would be nice to check and warn that this
     does not make sense to specify.



(Token horizontal diffs)

   * Token horizontal diffs computation option (idea from idanan)

   * Case-sensitive Horizontal diffs?



(Web site)

   * Add emacs trick to start xxdiff automatically on previous file

   * Add to google direcotry!!!

   * Add directories
   * From freshmeat, "run query" link
   * Links from Perfore web site

   * Add link to apps.kde.com entry (which is pretty much up-to-date).


(Improve options dialog synchronization)

   * Sync options dialog

     * For options dialog, on synchronize() we should really only update the
       controls which haven't been changed.  how do we do that?  perhaps have it
       work on a different resources object?

     * Apply display box resets horizontal diffs...
       Options dialog has to update on resources changes...
       ... figure out something with a second copy of the resources object.


(Try using Mightnight Commander backend)

> *  If xxdiff calls the vfs layer of midnight commander instead of
>    unix filesystem functions directly, it could enter and compare
>    even archive contents and ftp servers.
>    The libfs-mc.so is a sub project within mc and independent
>    of mc.
>
>    The required changes to the existing xxdiff code are an
>    exchange  of the unix calls with their vsf counter parts and
>    one initialization/shutdown call at start and program end.
>
>    eg:   open(..) becomes  mc_open(..),


(Internal diffs)

   * Enable internal GNU diff as a runtime option

   * Implement the 3-way and dir. version of this (not done yet)

   * Internal diff: must set status with correct values as external diff
     this currently does not work with files being the same


(Port to Qt-3.0)

   * Implement reading process output with QProcess

   * Port to Windows using the Qt Non-commercial license 3.0, or mingw32


(Misc GUI stuff)

   * Add an option to draw a pattern within empty lines, to make them stand out
     more (not just a color).

   * While selecting the colors, implement a color picker so you could select a
     color in the text view

   * Add support for wheel events, even in overview area.

   * Add an easter egg, pretty much noone ever looks at the source code.

   * Allow selection of text, as in an editor, just for cut-n-paste purpose
     (line based only though).

   * Selecting many lines in a big hunk one-by-one is lame.
     Do something at the same time that you implement region selection.
     Extended selection (on mouse release normal click except when straddling
     lines) allow larger selection (smarter key down/up processing).
     Region Selection for the purpose of cut-n-paste.

   * Add invert selection functionality

   * "What's this?" on a file widget should babble about the specific region
     which was clicked on.

   * It would be nice to be able to select both sides of a hunk for making
     merge comments... but thru which UI do we do this?

   * Popup menu should implement selection instead of motion commands, maybe
     depending on if clicked on an IGNORE region or not;

   * Add more/less contrast buttons for easy changing all colors simulatneously
     for horizontal diffs.


(Search results)

   * Make each line able to contain multiple search results instances (a list).

   * Draw brackets around search results, over text area, highlighting search
     results.

   * Add case sensitivity to search feature.

   * Search using regexp.

   * Add a status bar -like widgets line at the bottom, with exclude lineedits
     and search widgets, and make it work a la emacs.


(Ignore regexp/pattern)

   * Use display-ignore feature to ignore certain regexp

   * Use display-ignore feature to ignore change from regexp A to regexp B
     (gijsbert)

   * Add a line at the bottom for interactive search widget and ignore pattern
     widgets (line edits)


(Documentation)

   * Rename "regions" to "hunks" and use GNU diff terminology from texinfo

   * Open left/right on an empty xxdiff should allow to open!
     Supporting one file only.  (on startup AND on an open diff) this can be
     done easily by specifying the "other" file as an empty file and running
     the current diff parser.

   * Add an option for splitting all CHANGE regions automatically (buh?)

   * Add an option to display context format diffs into its own widget, like
     for the line numbers.

   * allow insertion of marker lines

   * Add save options for save selected only file dialog;

   * Keep the cursor line in region after swap->merge transition;

   * feature: show only hunks, collapse ignore regions...

   * feature: ignore diffs from "this" to "that" (-I option) should we have a
     different color for ignored diffs?  say e.g. case insensitivity done at the
     xxdiff level (for that the ``ignore'' algorithm must be done by xxdiff
     itself)


(More checks and verification)

   * Check if can parse context, ed, normal, or unified diffs output, the user
     might specify such an erroneous command;




--------------------------------------------------------------------------------
Tasks: Merged view improvements.

(Quick save merged results)

   > Merged file name parameter
   >
   >
   >  I have tried xxdiff with CM/Synergy. Horizontal diffs
   > are really neat. Furthermore it would be nice to have a
   > default output file parameter (like -o filename) for
   > the merge operation and a save button to write output
   > to this file.
   >
   >
   > Message
   >
   >
   >
   > Date: 2001-11-20 14:03
   > Sender: blais
   > Logged In: YES
   > user_id=10996
   >
   > Sounds like an easy feature to implement.
   >
   > I assume that what you want is a default filename so that
   > you don't have to type it in when you save.  The way it
   > could work is that this new save button would not pop the
   > file dialog, and would save to some default name, like
   > "<filename>.merge" in ClearCase, or the filename
   > you
   > specified as an option  (of course, if the file already
   > exists, it would pop a warning).  Sounds reasonable.  I
   > would also add a menu entry for this kind of fast save.
   >
   > I guess you'd also want an option to save automatically if
   > the merge succeeded without conflicts, without even
   > showing the UI at all?  I wanted to do this eventually
   > from a script from the outside, but if you'd know what
   > filename to save merged results to, I find it would
   > reasonable to support this.
   >
   > For quick access to that special save as feature I'd add a
   > button in the existing toolbar.
   >
   > Any more ideas let me know.  They will certainly be
   > considered seriously.  I'm in feature mode these days...
   >
   >
   >
   >
   >
   > Date: 2001-11-21 05:04
   > Sender: nobody
   > Logged In: NO
   >
   > This is exactly the way CM/Synergy works. You specify a
   > template for merge command with placeholders for file
   > revision names, inclusive the name of the temporary output
   > file. What you need to do is only to say "Save" after
   > you
   > done and a new revision will be created from that output
   > file. With this feature is xxdiff far superior to vendor
   > supplied diff tool.
   > I have 2 suggestions about usability:
   > 1. Mouse wheel for the right scrollbar. You have two
   > scrollbars in the application, in the middle of the main
   > window and on the right side. In most cases I have the right
   > scrollbar enabled and I prefer it over the middle scrollbar,
   > because it is common for the most applications. With the
   > middle scrollbar I can scroll with the mouse wheel, with the
   > right I can only drag. Please make the mouse wheel work for
   > the right scroll bar.
   > 2. Compact view. Is it possible to introduce a compact view
   > mode, where only the differences between files are visible?
   > I would go so far to say, this should be the default mode
   > and only when you need, you can expand the view to full
   > (current) mode. If it already works, and I miss some
   > parameter please insert a remark in the FAQ about how to do
   > this.
   >
   >
   >
   > Date: 2001-11-21 08:21
   > Sender: blais
   > Logged In: YES
   > user_id=10996
   >
   > 0. Cool.  I don't think xxdiff will create a new revision
   > automatically though, if I'm not mistaken, the way
   > ClearCase's xcleardiff works is by just leaving the saved
   > file checked out, then when you check it in, it will
   > create the merge arrow/dependency in the database.  How
   > would it work for CM/Synergy?  In other words, do their
   > diff program need to do something special apart from just
   > saving out the merged results to a file?
   >
   > 1. Mouse wheel support.  I'll do it eventually.  The
   > scrollbar on the right is all implemented "by hand",
   > it is
   > part of the overview display and I added this scrollbar
   > like behaviour after.   This is why it doesn't work right
   > now.  I think it will be easy to do though.
   >
   > 2. Doesn't just using the "n" and "p" keys
   > work just right
   > for that?  It just skips to the next/previous change.
   > That's what we do at discreet, and most seem happy abuot
   > it.
   >
   > Thanks for keeping the dialog, this in the end will help
   > make xxdiff a better product.  I plan to eventually add
   > some kind of support for most CM systems, but only when
   > I'm done with non-CM specific features (e.g. patch input
   > and output).



(Misc)

   * Rewrite rendering engine for merged view like the text one!  can we share
     the code?


   * Merged view option to draw all hunk texts instead of men-at-work pattern

   * Fix all issues raised in merged.cpp FIXME comments.

   * Merged view: the motion commands should work from the merged view.

   * Selection commands should work too

   * Scrolling the merged view should scroll the other view as well.

   * Merged view cannot mouse-drag properly.  Implement a more viable solution
     that will allow to to the inverse drag as well, perhaps setting up a
     publicly-available indirection table in the XxDiffs object.

   * Merged view: add different colors for different selected sides

   * Merged view: display both regions in merged view when unselected
     (as an option)

   * Add "show merged view on startup" resource.

   * Merged view: should have the option of seeing both files' hunks instead of
     "work" lines.


(One-Pane View)

   * Support one-pane view, where both selections are shown together in one text
     view.  Do this for merged view only.  Perhaps allow selection there.


--------------------------------------------------------------------------------
Tasks: Editing

   * Implement some editing in the merged view!!

> Re: [xxdiff/perso] Changing merged output manually?
> From: Xavier Outhier <xavier.outhier@anfdata.cz>
>  To: Martin Blais <blais@discreet.com>
>  Date: Tue, 22 Jan 2002 09:27:53 +0100
>
> Martin Blais wrote:
> >
> > On Monday 21 January 2002 07:06, you wrote:
> > > Hi,
> > >
> > > I have a question about xxdiff
> > > (http://sourceforge.net/projects/xxdiff/).
> > >
> > > Is it possible to change the merged file
> > > manually. I mean to be able to add text
> > > that is not in any of the 2 or 3 files
> > > compared. This is sometime very useful.
> > >
> > > I haven't see that (clearly) in the online
> > > documentation. I think this will be a very
> > > interesting item for the FAQ.
> > >
> > > I'm using ClearCase at work and from this
> > > point of view clearmerge is really good.
> > > But for me, I would prefer some tool under
> > > GPL.
> >
> > nope, you cannot. the rationale behind this is that I don't
> > want xxdiff to become an editor.
>
> It would be a logical evolution, wouldn't it?
> I mean for the merge window only.
>
> >  i'd like to eventually make it able to do very simple
> > editing (and to limit it to that).
> >
> > you can, however, click on the filename widgets to put
> > them in the clipboard and then paste into a shell for
> > editing the file.
>
> Not very friendly way and error prone I suppose.
>
> > let me know the minimal editing capabilities you would
> > like to have and i'll consider it on the todo list.
>
> For me the minimum would be to able to add a complete
> line anywhere in the merged window.
> Maybe this can be only before or after the diff line from
> the sources to be merged.
> A special highlighting should be provided in order to
> make the difference between original code (from the sources)
> and the user added lines.
>
> Possibility to add nay number of line instead of one would
> be better of course.
>
> This excludes adding lines in diff parts if multiple-lines.
> This also excludes adding/changing any section of text
> in existing lines.
>
> Is it reasonnable?
> What's your estimation of difficulty and amount of time
> to make the change?
> What if some contributor do it?
>
> - Again a question: What's the difference between rmp in
> different Linux distribution? I'm running SuSE 7.2. I might
> be interested in preparing rpm for SuSE. Is it worth to do it?
>
>
> Regards,
>
> Xavier.
>
> PS: tu parles francais?
> --
> D2SET Scientific and Technical Non profit Association
>  http://www.d2set.org/
>  mailto:d2set@d2set.org
>
> Artificial Anthill Project
>  http://www.aanthill.org/
>  mailto:aanthill@aanthill.org
>




--------------------------------------------------------------------------------
Tasks: Patch support.

(Patch application idea)

Oded Arbel <oded@geek.co.il>
> BTW - in MS-Windows I use this pretty nice diff program called WinMerge,
> and its one cool feature is that I can tell it to copy the selected
> difference from one of the files to the other - actually being a "manual"
> merge tool. it would be really nice if xxdiff had this feature - I like to
> be able to selectibly apply partial differences w/o going to the trouble of
> editing patch files by hand.


(Patch input support)

   * Make it able to read in a patch and apply it, without the second file

   * Allow diff using a patch file, even containing a patch for many files
     (easy: you could let patch patch the file on stdout, grab the output and
     perform normal diff)


(Patch output support)

   * Make it able to output a patch


--------------------------------------------------------------------------------
Tasks: Directory diffs improvements and bug fixing.

(Directory Diffs Misc)

   * Don't show vertical line on directory diffs!

   * In dirdiffs mode, cut-n-paste should just put the clicked filename (one
     side) in the clipboard, without the \n.

   * Launching xxdiff dirs with two same directories results in an empty buffer
     thingy, because diff itself just silently returns.

   * New functionality that spawns a bunch of diffs for all the changed files
     in a directory (dirdiffs only).

   * In dir diffs, remove toolbar buttons, selection menus, open file must be
     able to select a directory, etc. IOW finish checking that all that is left
     works.

   * Add exclude option to diff options

     > 2. Running "xxdiff dir1/*.c dir2/*.c caused seg. fault.
     >     "dirdiff", available at freshmeat.net, runs with no problem.
     >
     > Thanh Ma wrote:
     > >
     > > Hi,
     > >
     > > 2. Running "xxdiff dir1/*.c dir2/*.c caused seg. fault.
     > >     "dirdiff", available at freshmeat.net, runs with no problem.
     > >
     >
     > I found the bug for this one.  THis is a simple cmdline parsing bug I had
     > never found. Thanks again for reporting it.
     >
     > In any case, this should not work:  your shell expands the list of files, so
     > in effect your program get the whole list... how is it supposed to know which
     > list is on which side?  I guess it looks at the directory prefixes.
     >
     >  I wonder if it handles dirdiff dir1/*.c dir2/*.c dir3/some.c
     > In any case, an ignore pattern will be implemented eventually to do the same
     > as what you're asking.  When I get that done I'll probably extend the cmdline
     > interface to do like diff does.  GNU diff doesn't handle this cmdline
     > interface:
     >
     >
     > taiwan:/DLlocal/.../xxdiff/test$ diff -q -r d1/*.c d2/*.c
     > diff: extra operand
     > diff: Try `diff --help' for more information.

   * Show symlinks, date and size of files in directory diffs

   * Add an icon somewhere to show if a directory diff or a simple file diff

   * Add a file viewer command for dirdiff to spawn on inserts and deletes in
     dirdiff mode!  That would be great!


--------------------------------------------------------------------------------
Tasks: CM integration

(CVS revisions browsing)

   * Write independent app running in a different process to dnd CVS revisions

   * Make the text area a drop site for files, so files from the other guy or
     from some file manager could be dropped right into it and be diffed
     automatically.  This will require some non-trivial temporary file diddling.

(Xxscripts)

   * Implement xxcvs update.

   * CVS and Clearcase: write interface/protocol scripts

   * Mv xxct to xxcleartool and implement using distutils

   * Separate cvs stuff from xxcvs into cvslib, use distutils

(General CM support)

   * Some features:

     | Peter Becker wrote:
     | >
     | > > Anyway, my question:
     | > >
     | > > I want to implement some support for CM systems, in particular ClearCase and
     | > > CVS. I wish to implement this in a generic manner, in order to support
     | > > multiple CM systems.
     | > >
     | > > I need your input: what CM-related features would you like to see supported in
     | > > a file comparison program?  Here's what I'm thinking of:
     | > >
     | > >  - revision tree listing i.e. looking at the history
     | > >    of revisions
     | > >
     | > >  - automatic version extraction i.e. being able
     | > >    to switch which version of file xxdiff is
     | > >    diffing with, probably by clicking in the
     | > >    revision tree listing
     | > >
     | > >  - ability to checkout latest version (prior to saving
     | > >    a merge result).
     | > >
     | > >  - All CM commands should be run in background in case
     | > >    of slow access to CM server
     | > >
     | > > Anything else?  Please let me know, I want to know what could be useful to
     | > > you.  Any comments appreciated.
     |
     |
     |
     | > Something we use all the time is cvs edit -- it would be useful for us if a merge
     | > tool can handle read-only checkout and edit/unedit.
     |
     | When I mentioned "checkout" above, in cvs it's called "edit", so we're talking
     | about the same thing:
     |
     | >From cvs documentation:
     | > you are planning to edit it, use the `cvs edit' command.  Some systems
     | > call this a "checkout", but CVS uses that term for obtaining a copy of
     | > the sources (*note Getting the source::.), an operation which those
     | > systems call a "get" or a "fetch".
     |
     |
     | > Useful for the comparison of different versions of the program is a program that
     | > combines directory and file comparison -- the overview shows all files and if they
     | > are different, the files that are different can be opened in the file diff.
     |
     | xxdiff already does that.  If you call it on two directories, you can select
     | files and use the popup menu to get an xxdiff of the specific files.
     |
     | xxdiff also works recursively on directories.  It makes it really easy to
     | compare hierarchies this way (this is how I merge my configuration files, for
     | example).
     |
     | However, you just gave me another idea: one may wish to compare tagged
     | versions, as a directory diff, e.g. compare hierarchy with 1.8 tag and 1.9
     | tag.  I'll look into how I could do this. This would be a cool feature.  Do
     | you get it?  for example, you could spawn a directory diff in your current
     | directory, asking xxdiff to compare with the latest tagged versions.



(Annotations)

   * Somehow support annotations within xxdiff, with input perhaps from some
     script, perhaps integrated from C++.

     | >
     | > Some nice but really not important feature: connecting the lines of the code with
     | > the last changes (and their logs). This is useful if you ask yourself: what is
     | > this code for? But maybe this feature shouldn't go into a diff tool.
     |
     | Surely it could be nice to be able to extract and display the log comments for
     | shown revisions, good idea! I'll add it in.



(Binary Diffs)

   * Idea (plante@iro): Pour faire des diffs de fichiers binaires...
     Sers-toi d'un programme qui fait des hexdumps (sur linux il y a xxd), et
     fais le diff la-dessus. Ça marche bien.