/* mhfixmsg.c -- rewrite a message with various transformations
 *
 * This code is Copyright (c) 2002 and 2013, by the authors of nmh.
 * See the COPYRIGHT file in the root directory of the nmh
 * distribution for complete copyright information.
 */

#include "h/mh.h"
#include "sbr/charstring.h"
#include "sbr/check_charset.h"
#include "sbr/m_name.h"
#include "sbr/m_gmprot.h"
#include "sbr/m_getfld.h"
#include "sbr/getarguments.h"
#include "sbr/concat.h"
#include "sbr/seq_setprev.h"
#include "sbr/seq_setcur.h"
#include "sbr/seq_save.h"
#include "sbr/smatch.h"
#include "sbr/encode_rfc2047.h"
#include "sbr/fmt_rfc2047.h"
#include "sbr/cpydata.h"
#include "sbr/trimcpy.h"
#include "sbr/m_convert.h"
#include "sbr/m_backup.h"
#include "sbr/getfolder.h"
#include "sbr/folder_read.h"
#include "sbr/context_save.h"
#include "sbr/context_replace.h"
#include "sbr/context_find.h"
#include "sbr/readconfig.h"
#include "sbr/ambigsw.h"
#include "sbr/path.h"
#include "sbr/print_version.h"
#include "sbr/print_help.h"
#include "sbr/error.h"
#include "sbr/fmt_compile.h"
#include "sbr/fmt_scan.h"
#include "h/mime.h"
#include "h/mhparse.h"
#include "sbr/done.h"
#include "sbr/utils.h"
#include <signal.h>
#include "sbr/signals.h"
#include "sbr/m_maildir.h"
#include "sbr/m_mktemp.h"
#include "sbr/mime_type.h"
#include "mhmisc.h"
#include "mhfree.h"
#include "mhoutsbr.h"
#include "mhshowsbr.h"
#include <fcntl.h>
#include "sbr/globals.h"

#define MHFIXMSG_SWITCHES \
    X("decodetext 8bit|7bit|binary", 0, DECODETEXTSW) \
    X("nodecodetext", 0, NDECODETEXTSW) \
    X("decodetypes", 0, DECODETYPESW) \
    X("decodeheaderfieldbodies charset", 0, DECODEHEADERFIELDBODIESSW) \
    X("nodecodeheaderfieldbodies", 0, NDECODEHEADERFIELDBODIESSW) \
    X("crlflinebreaks", 0, CRLFLINEBREAKSSW) \
    X("nocrlflinebreaks", 0, NCRLFLINEBREAKSSW) \
    X("textcharset", 0, TEXTCHARSETSW) \
    X("notextcharset", 0, NTEXTCHARSETSW) \
    X("reformat", 0, REFORMATSW) \
    X("noreformat", 0, NREFORMATSW) \
    X("replacetextplain", 0, REPLACETEXTPLAINSW) \
    X("noreplacetextplain", 0, NREPLACETEXTPLAINSW) \
    X("fixboundary", 0, FIXBOUNDARYSW) \
    X("nofixboundary", 0, NFIXBOUNDARYSW) \
    X("fixcte", 0, FIXCOMPOSITECTESW) \
    X("nofixcte", 0, NFIXCOMPOSITECTESW) \
    X("checkbase64", 0, CHECKBASE64SW) \
    X("nocheckbase64", 0, NCHECKBASE64SW) \
    X("fixtype mimetype", 0, FIXTYPESW) \
    X("file file", 0, FILESW) \
    X("outfile file", 0, OUTFILESW) \
    X("rmmproc program", 0, RPROCSW) \
    X("normmproc", 0, NRPRCSW) \
    X("changecur", 0, CHGSW) \
    X("nochangecur", 0, NCHGSW) \
    X("verbose", 0, VERBSW) \
    X("noverbose", 0, NVERBSW) \
    X("version", 0, VERSIONSW) \
    X("help", 0, HELPSW) \

#define X(sw, minchars, id) id,
DEFINE_SWITCH_ENUM(MHFIXMSG);
#undef X

#define X(sw, minchars, id) { sw, minchars, id },
DEFINE_SWITCH_ARRAY(MHFIXMSG, switches);
#undef X


int verbosw;
bool debugsw; /* Needed by mhparse.c. */

#define quitser pipeser

/*
 * static prototypes
 */
typedef struct {
    int reformat;
    int replacetextplain;
    char *textcharset;
} text_properties;
typedef struct {
    int fixboundary;
    int fixcompositecte;
    svector_t fixtypes;
    text_properties text_props;
    int decodetext;
    char *decodetypes;
    char *decodeheaderfieldbodies; /* Either NULL or the destination charset. */
    /* Whether to use CRLF linebreaks, per RFC 2046 Sec. 4.1.1, par.1. */
    int lf_line_endings;
    bool checkbase64;
} fix_transformations;

static int mhfixmsgsbr (CT *, char *, const fix_transformations *,
    FILE **, char *, FILE **);
static int fix_boundary (CT *, int *);
static int copy_input_to_output (const char *, FILE *, const char *, FILE *);
static int get_multipart_boundary (CT, char **);
static int replace_boundary (CT, char *, char *);
static int fix_types (CT, svector_t, int *);
static char *replace_substring (char **, const char *, const char *);
static char *remove_parameter (char *, const char *);
static int fix_composite_cte (CT, int *);
static int set_ce (CT, int);
static int ensure_text_plain (CT *, CT, int *, const text_properties *);
static int find_textplain_sibling (CT, int, int *);
static int insert_new_text_plain_part (CT, int, CT, const text_properties *);
static CT build_text_plain_part (CT, const text_properties *);
static int insert_into_new_mp_alt (CT *, int *, const text_properties *);
static int insert_into_new_mp_mixed (CT *, const char *, int *);
static CT divide_part (CT);
static void copy_ctinfo (CI, CI);
static int decode_part (CT);
static size_t get_valid_base64 (CT, char **);
static size_t find_invalid_base64_pos (const char *);
static int check_base64_encoding (CT *);
static int reformat_part (CT, char *, char *, char *, int, const text_properties *);
static CT build_multipart (CT, CT, int, int);
static int boundary_in_content (FILE **, char *, const char *);
static void transfer_noncontent_headers (CT, CT);
static int set_ct_type (CT, int type, int subtype, int encoding, const char *charset);
static int decode_text_parts (CT, int, const char *, int *);
static int should_decode(const char *, const char *, const char *);
static int content_encoding (CT, const char **);
static int strip_crs (CT, int *);
static void update_cte (CT);
static int least_restrictive_encoding (CT) PURE;
static int less_restrictive (int, int);
static int convert_charsets (CT, char *, int *);
static int fix_always (CT *, const fix_transformations *, int *);
static int decode_header_field_bodies (CT, const char *, int *);
static int decode_field_body (const char *, char **, const char *, int *);
static bool contains_nuls(const char *, ssize_t);
static int fix_filename_param (char *, char *, PM *, PM *);
static int fix_filename_encoding (CT);
static int write_content (CT, const char *, char *, FILE *, int, int);
static void set_text_ctparams(CT, char *, int);
static int remove_file (const char *);
static void report (char *, char *, char *, char *, ...)
    CHECK_PRINTF(4, 5);
static void pipeser (int);


int
main (int argc, char **argv)
{
    int msgnum;
    char *cp, *file = NULL, *folder = NULL;
    char *maildir = NULL, buf[100], *outfile = NULL;
    char **argp, **arguments;
    struct msgs_array msgs = { 0, 0, NULL };
    struct msgs *mp = NULL;
    CT *ctp;
    FILE *fp, *infp = NULL, *outfp = NULL;
    bool using_stdin = false;
    bool chgflag = true;
    int status = OK;
    fix_transformations fx;
    fx.text_props.reformat = fx.fixcompositecte = fx.fixboundary = 1;
    fx.text_props.replacetextplain = 0;
    fx.text_props.textcharset = NULL;
    fx.fixtypes = NULL;
    fx.decodetext = CE_8BIT;
    fx.decodetypes = "text,application/ics";  /* Default, per man page. */
    fx.decodeheaderfieldbodies = NULL;
    fx.lf_line_endings = 0;
    fx.checkbase64 = true;

    if (nmh_init(argv[0], true, false)) { return 1; }

    arguments = getarguments (invo_name, argc, argv, 1);
    argp = arguments;

    /*
     * Parse arguments
     */
    while ((cp = *argp++)) {
        if (*cp == '-') {
            switch (smatch (++cp, switches)) {
            case AMBIGSW:
                ambigsw (cp, switches);
                done (1);
            case UNKWNSW:
                die("-%s unknown", cp);

            case HELPSW:
                snprintf (buf, sizeof buf, "%s [+folder] [msgs] [switches]",
                        invo_name);
                print_help (buf, switches, 1);
                done (0);
            case VERSIONSW:
                print_version(invo_name);
                done (0);

            case DECODETEXTSW:
                if (! (cp = *argp++)  ||  *cp == '-') {
                    die("missing argument to %s", argp[-2]);
                }
                if (! strcasecmp (cp, "8bit")) {
                    fx.decodetext = CE_8BIT;
                } else if (! strcasecmp (cp, "7bit")) {
                    fx.decodetext = CE_7BIT;
                } else if (! strcasecmp (cp, "binary")) {
                    fx.decodetext = CE_BINARY;
                } else {
                    die("invalid argument to %s", argp[-2]);
                }
                continue;
            case NDECODETEXTSW:
                fx.decodetext = 0;
                continue;
            case DECODETYPESW:
                if (! (cp = *argp++)  ||  *cp == '-') {
                    die("missing argument to %s", argp[-2]);
                }
                fx.decodetypes = cp;
                continue;
            case DECODEHEADERFIELDBODIESSW:
                if (! (cp = *argp++)  ||  *cp == '-') {
                    die("missing argument to %s", argp[-2]);
                }
                fx.decodeheaderfieldbodies = cp;
                continue;
            case NDECODEHEADERFIELDBODIESSW:
                fx.decodeheaderfieldbodies = NULL;
                continue;
            case CRLFLINEBREAKSSW:
                fx.lf_line_endings = 0;
                continue;
            case NCRLFLINEBREAKSSW:
                fx.lf_line_endings = 1;
                continue;
            case TEXTCHARSETSW:
                if (! (cp = *argp++) || (*cp == '-' && cp[1])) {
                    die("missing argument to %s", argp[-2]);
                }
                fx.text_props.textcharset = cp;
                continue;
            case NTEXTCHARSETSW:
                fx.text_props.textcharset = NULL;
                continue;
            case CHECKBASE64SW:
                fx.checkbase64 = true;
                continue;
            case NCHECKBASE64SW:
                fx.checkbase64 = false;
                continue;
            case FIXBOUNDARYSW:
                fx.fixboundary = 1;
                continue;
            case NFIXBOUNDARYSW:
                fx.fixboundary = 0;
                continue;
            case FIXCOMPOSITECTESW:
                fx.fixcompositecte = 1;
                continue;
            case NFIXCOMPOSITECTESW:
                fx.fixcompositecte = 0;
                continue;
            case FIXTYPESW:
                if (! (cp = *argp++) || (*cp == '-' && cp[1])) {
                    die("missing argument to %s", argp[-2]);
                }
                if (! strncasecmp (cp, "multipart/", 10)  ||
                    ! strncasecmp (cp, "message/", 8))
                    die("-fixtype %s not allowed", cp);
                if (! strchr (cp, '/'))
                    die("-fixtype requires type/subtype");
                if (fx.fixtypes == NULL) { fx.fixtypes = svector_create (10); }
                svector_push_back (fx.fixtypes, cp);
                continue;
            case REFORMATSW:
                fx.text_props.reformat = 1;
                continue;
            case NREFORMATSW:
                fx.text_props.reformat = 0;
                continue;
            case REPLACETEXTPLAINSW:
                fx.text_props.replacetextplain = 1;
                continue;
            case NREPLACETEXTPLAINSW:
                fx.text_props.replacetextplain = 0;
                continue;
            case FILESW:
                if (! (cp = *argp++) || (*cp == '-' && cp[1])) {
                    die("missing argument to %s", argp[-2]);
                }
                file = *cp == '-'  ?  mh_xstrdup (cp)  :  path (cp, TFILE);
                continue;
            case OUTFILESW:
                if (! (cp = *argp++) || (*cp == '-' && cp[1])) {
                    die("missing argument to %s", argp[-2]);
                }
                outfile = *cp == '-'  ?  mh_xstrdup (cp)  :  path (cp, TFILE);
                continue;
            case RPROCSW:
                if (!(rmmproc = *argp++) || *rmmproc == '-') {
                    die("missing argument to %s", argp[-2]);
                }
                continue;
            case NRPRCSW:
                rmmproc = NULL;
                continue;
            case CHGSW:
                chgflag = true;
                continue;
            case NCHGSW:
                chgflag = false;
                continue;
            case VERBSW:
                verbosw = 1;
                continue;
            case NVERBSW:
                verbosw = 0;
                continue;
            }
        }
        if (*cp == '+' || *cp == '@') {
            if (folder)
                die("only one folder at a time!");
            folder = pluspath (cp);
        } else {
            if (*cp == '/') {
                /* Interpret a full path as a filename, not a message. */
                file = mh_xstrdup (cp);
            } else {
                app_msgarg (&msgs, cp);
            }
        }
    }

    SIGNAL (SIGQUIT, quitser);
    SIGNAL (SIGPIPE, pipeser);

    /*
     * Read the standard profile setup
     */
    if ((fp = fopen (cp = etcpath ("mhn.defaults"), "r"))) {
        readconfig(NULL, fp, cp, 0);
        fclose (fp);
    }

    suppress_bogus_mp_content_warning = skip_mp_cte_check = true;
    suppress_extraneous_trailing_semicolon_warning = true;

    if (! context_find ("path")) {
        free (path ("./", TFOLDER));
    }

    if (file && msgs.size) {
        die("cannot specify msg and file at same time!");
    }

    if (outfile) {
        /* Open the outfile now, so we don't have to risk opening it
           after running out of fds. */
        if (strcmp (outfile, "-") == 0) {
            outfp = stdout;
        } else if ((outfp = fopen (outfile, "w")) == NULL) {
            adios (outfile, "unable to open for writing");
        }
    }

    /*
     * check if message is coming from file
     */
    if (file) {
        /* If file is stdin, create a tmp file name before parse_mime()
           has a chance, because it might put in on a different
           filesystem than the output file.  Instead, put it in the
           user's preferred tmp directory. */
        CT ct;

        if (! strcmp ("-", file)) {
            int fd;
            char *cp;

            using_stdin = true;

            if ((cp = m_mktemp2 (NULL, invo_name, &fd, NULL)) == NULL) {
                die("unable to create temporary file in %s",
                       get_temp_dir());
            } else {
                free (file);
                file = mh_xstrdup (cp);
                cpydata (STDIN_FILENO, fd, "-", file);
            }

            if (close (fd)) {
                (void) m_unlink (file);
                die("failed to write temporary file");
            }
        }

        cts = mh_xcalloc(2, sizeof *cts);
        ctp = cts;

        if ((ct = parse_mime (file))) {
            set_text_ctparams(ct, fx.decodetypes, fx.lf_line_endings);
            *ctp++ = ct;
        } else {
            inform("unable to parse message from file %s", file);
            status = NOTOK;

            /* If there's an outfile, pass the input message unchanged, so the
               message won't get dropped from a pipeline. */
            if (outfile) {
                /* Something went wrong.  Output might be expected, such as if
                   this were run as a filter.  Just copy the input to the
                   output. */
                if ((infp = fopen (file, "r")) == NULL) {
                    adios (file, "unable to open for reading");
                }

                if (copy_input_to_output (file, infp, outfile, outfp) != OK) {
                    inform("unable to copy message to %s, "
                            "it might be lost", outfile);
                }

                fclose (infp);
                infp = NULL;
            }
        }
    } else {
        /*
         * message(s) are coming from a folder
         */
        CT ct;

        if (! msgs.size) {
            app_msgarg(&msgs, "cur");
        }
        if (! folder) {
            folder = getfolder (1);
        }
        maildir = mh_xstrdup(m_maildir (folder));

        /* chdir so that error messages, esp. from MIME parser, just
           refer to the message and not its path. */
        if (chdir (maildir) == -1) {
            adios (maildir, "unable to change directory to");
        }

        /* read folder and create message structure */
        if (! (mp = folder_read (folder, 1))) {
            die("unable to read folder %s", folder);
        }

        /* check for empty folder */
        if (mp->nummsg == 0) {
            die("no messages in %s", folder);
        }

        /* parse all the message ranges/sequences and set SELECTED */
        for (msgnum = 0; msgnum < msgs.size; msgnum++)
            if (! m_convert (mp, msgs.msgs[msgnum])) {
                done (1);
            }
        seq_setprev (mp);       /* set the previous-sequence */

        cts = mh_xcalloc(mp->numsel + 1, sizeof *cts);
        ctp = cts;

        for (msgnum = mp->lowsel; msgnum <= mp->hghsel; msgnum++) {
            if (is_selected(mp, msgnum)) {
                char *msgnam = m_name (msgnum);

                if ((ct = parse_mime (msgnam))) {
                    set_text_ctparams(ct, fx.decodetypes, fx.lf_line_endings);
                    *ctp++ = ct;
                } else {
                    inform("unable to parse message %s", msgnam);
                    status = NOTOK;

                    /* If there's an outfile, pass the input message
                       unchanged, so the message won't get dropped from a
                       pipeline. */
                    if (outfile) {
                        /* Something went wrong.  Output might be expected,
                           such as if this were run as a filter.  Just copy
                           the input to the output. */
                        /* Can't use path() here because 1) it might have been
                           called before and it caches the pwd, and 2) we call
                           chdir() after that. */
                        char *input_filename =
                            concat (maildir, "/", msgnam, NULL);

                        if ((infp = fopen (input_filename, "r")) == NULL) {
                            adios (input_filename,
                                   "unable to open for reading");
                        }

                        if (copy_input_to_output (input_filename, infp,
                                                  outfile, outfp) != OK) {
                            inform("unable to copy message to %s, "
                                "it might be lost", outfile);
                        }

                        fclose (infp);
                        infp = NULL;
                        free (input_filename);
                    }
                }
            }
        }

        if (chgflag) {
            seq_setcur (mp, mp->hghsel);  /* update current message */
        }
        seq_save (mp);                    /* synchronize sequences  */
        context_replace (pfolder, folder);/* update current folder  */
        context_save ();                  /* save the context file  */
    }

    if (*cts) {
        for (ctp = cts; *ctp; ++ctp) {
            status =
                mhfixmsgsbr (ctp, maildir, &fx, &infp, outfile, &outfp) == OK
                ? 0
                : 1;
            free_content (*ctp);

            if (using_stdin) {
                (void) m_unlink (file);

                if (! outfile) {
                    /* Just calling m_backup() unlinks the backup file. */
                    (void) m_backup (file);
                }
            }
            if (outfp) {
                /* close fp opened by the m_mktemp2() call in mhfixmsgsbr() */
                fclose (outfp);
                outfp = NULL;
            }
        }
    } else {
        status = 1;
    }

    free(maildir);
    free (cts);

    if (fx.fixtypes != NULL) { svector_free (fx.fixtypes); }
    if (infp) { fclose (infp); }    /* even if stdin */
    if (outfp) { fclose (outfp); }  /* even if stdout */
    free (outfile);
    free (file);
    free (folder);
    free (arguments);

    done (status == OK ? 0 : 1);
    return NOTOK;
}


/*
 * Apply transformations to one message.
 */
static int
mhfixmsgsbr (CT *ctp, char *maildir, const fix_transformations *fx,
             FILE **infp, char *outfile, FILE **outfp)
{
    /* Store input filename in case one of the transformations, i.e.,
       fix_boundary(), rewrites to a tmp file. */
    char *input_filename = maildir
        ?  concat (maildir, "/", (*ctp)->c_file, NULL)
        :  mh_xstrdup ((*ctp)->c_file);
    bool modify_inplace = false;
    int message_mods = 0;
    int status = OK;

    /* Though the input file won't need to be opened if everything goes
       well, do it here just in case there's a failure, and that failure is
       running out of file descriptors. */
    if ((*infp = fopen (input_filename, "r")) == NULL) {
        adios (input_filename, "unable to open for reading");
    }

    if (outfile == NULL) {
        modify_inplace = true;

        if ((*ctp)->c_file) {
            char *tempfile;
            /* outfp will be closed by the caller */
            if ((tempfile = m_mktemp2 (NULL, invo_name, NULL, outfp)) ==
                NULL) {
                die("unable to create temporary file in %s",
                       get_temp_dir());
            }
            outfile = mh_xstrdup (tempfile);
        } else {
            die("missing both input and output filenames");
        }
    } /* else *outfp was defined by caller */

    reverse_alternative_parts (*ctp);
    status = fix_always (ctp, fx, &message_mods);
    if (status == OK  &&  fx->fixboundary) {
        status = fix_boundary (ctp, &message_mods);
    }
    if (status == OK  && fx->fixtypes != NULL) {
        status = fix_types (*ctp, fx->fixtypes, &message_mods);
    }
    if (status == OK  &&  fx->fixcompositecte) {
        status = fix_composite_cte (*ctp, &message_mods);
    }
    if (status == OK  &&  fx->text_props.reformat) {
        status =
            ensure_text_plain (ctp, NULL, &message_mods, &fx->text_props);
    }
    if (status == OK  &&  fx->decodetext) {
        status = decode_text_parts (*ctp, fx->decodetext, fx->decodetypes,
                                    &message_mods);
        update_cte (*ctp);
    }
    if (status == OK  &&  fx->decodeheaderfieldbodies) {
        status = decode_header_field_bodies(*ctp, fx->decodeheaderfieldbodies,
                                            &message_mods);
    }
    if (status == OK  &&  fx->text_props.textcharset != NULL) {
        status = convert_charsets (*ctp, fx->text_props.textcharset, &message_mods);
    }

    if (status == OK  &&  ! (*ctp)->c_umask) {
        /* Set the umask for the contents file.  This currently
           isn't used but just in case it is in the future. */
        struct stat st;

        if (stat ((*ctp)->c_file, &st) != -1) {
            (*ctp)->c_umask = ~(st.st_mode & 0777);
        } else {
            (*ctp)->c_umask = ~m_gmprot();
        }
    }

    /*
     * Write the content to a file
     */
    if (status == OK) {
        status = write_content (*ctp, input_filename, outfile, *outfp,
                                modify_inplace, message_mods);
    } else if (! modify_inplace) {
        /* Something went wrong.  Output might be expected, such
           as if this were run as a filter.  Just copy the input
           to the output. */
        if (copy_input_to_output (input_filename, *infp, outfile,
                                  *outfp) != OK) {
            inform("unable to copy message to %s, it might be lost",
                    outfile);
        }
    }

    if (modify_inplace) {
        if (status != OK) { (void) m_unlink (outfile); }
        free (outfile);
        outfile = NULL;
    }

    fclose (*infp);
    *infp = NULL;
    free (input_filename);

    return status;
}


/*
 * Copy input message to output.  Assumes not modifying in place, so this
 * might be running as part of a pipeline.
 */
static int
copy_input_to_output (const char *input_filename, FILE *infp,
                      const char *output_filename, FILE *outfp)
{
    int in = fileno (infp);
    int out = fileno (outfp);
    int status = OK;

    if (in != -1  &&  out != -1) {
        cpydata (in, out, input_filename, output_filename);
    } else {
        status = NOTOK;
    }

    return status;
}


/*
 * Fix mismatched outer level boundary.
 */
static int
fix_boundary (CT *ct, int *message_mods)
{
    struct multipart *mp;
    int status = OK;

    if (ct  &&  (*ct)->c_type == CT_MULTIPART  &&  bogus_mp_content) {
        mp = (struct multipart *) (*ct)->c_ctparams;

        /*
         * 1) Get boundary at end of part.
         * 2) Get boundary at beginning of part and compare to the end-of-part
         *    boundary.
         * 3) Write out contents of ct to tmp file, replacing boundary in
         *    header with boundary from part.  Set c_unlink to 1.
         * 4) Free ct.
         * 5) Call parse_mime() on the tmp file, replacing ct.
         */

        if (mp  &&  mp->mp_start) {
            char *part_boundary;

            if (get_multipart_boundary (*ct, &part_boundary) == OK) {
                char *fixed;

                if ((fixed = m_mktemp2 (NULL, invo_name, NULL, &(*ct)->c_fp))) {
                    if (replace_boundary (*ct, fixed, part_boundary) == OK) {
                        char *filename = mh_xstrdup ((*ct)->c_file);
                        CT fixed_ct;

                        free_content (*ct);
                        if ((fixed_ct = parse_mime (fixed))) {
                            *ct = fixed_ct;
                            (*ct)->c_unlink = 1;

                            ++*message_mods;
                            if (verbosw) {
                                report (NULL, NULL, filename,
                                        "fix multipart boundary");
                            }
                        } else {
                            *ct = NULL;
                            inform("unable to parse fixed part");
                            status = NOTOK;
                        }
                        free (filename);
                    } else {
                        inform("unable to replace broken boundary");
                        status = NOTOK;
                    }
                } else {
                    inform("unable to create temporary file in %s",
                            get_temp_dir());
                    status = NOTOK;
                }

                free (part_boundary);
            } else {
                /* Couldn't fix the boundary.  Report failure so that mhfixmsg
                   doesn't modify the message. */
                status = NOTOK;
            }
        } else {
            /* No multipart struct, even though the content type is
               CT_MULTIPART.  Report failure so that mhfixmsg doesn't modify
               the message. */
            status = NOTOK;
        }
    }

    return status;
}


/*
 * Find boundary at end of multipart.
 */
static int
get_multipart_boundary (CT ct, char **part_boundary)
{
    char buffer[NMH_BUFSIZ];
    char *end_boundary = NULL;
    off_t begin = (off_t) ct->c_end > (off_t) (ct->c_begin + sizeof buffer)
        ?  (off_t) (ct->c_end - sizeof buffer)
        :  (off_t) ct->c_begin;
    size_t bytes_read;
    int status = OK;

    /* This will fail if the boundary spans fread() calls.  NMH_BUFSIZ should
       be big enough, even if it's just 1024, to make that unlikely. */

    /* free_content() will close ct->c_fp if bogus MP boundary is fixed. */
    if (! ct->c_fp  &&  (ct->c_fp = fopen (ct->c_file, "r")) == NULL) {
        advise (ct->c_file, "unable to open for reading");
        return NOTOK;
    }

    /* Get boundary at end of multipart. */
    while (begin >= (off_t) ct->c_begin) {
        fseeko (ct->c_fp, begin, SEEK_SET);
        while ((bytes_read = fread (buffer, 1, sizeof buffer, ct->c_fp)) > 0) {
            char *cp = rfind_str (buffer, bytes_read, "--");

            if (cp) {
                char *end;

                /* Trim off trailing "--" and anything beyond. */
                *cp-- = '\0';
                if ((end = rfind_str (buffer, cp - buffer, "\n"))) {
                    if (strlen (end) > 3  &&  *end++ == '\n'  &&
                        *end++ == '-'  &&  *end++ == '-') {
                        end_boundary = mh_xstrdup (end);
                        break;
                    }
                }
            }
        }

        if (end_boundary  ||  begin <= (off_t) (ct->c_begin + sizeof buffer))
            break;
        begin -= sizeof buffer;
    }

    /* Get boundary at beginning of multipart. */
    if (end_boundary) {
        fseeko (ct->c_fp, ct->c_begin, SEEK_SET);
        while ((bytes_read = fread (buffer, 1, sizeof buffer, ct->c_fp)) > 0) {
            if (bytes_read >= strlen (end_boundary)) {
                char *cp = find_str (buffer, bytes_read, end_boundary);

                if (cp  &&  cp - buffer >= 2  &&  *--cp == '-'  &&
                    *--cp == '-'  &&  (cp > buffer  &&  *--cp == '\n')) {
                    status = OK;
                    break;
                }
            } else {
                /* The start and end boundaries didn't match, or the
                   start boundary doesn't begin with "\n--" (or "--"
                   if at the beginning of buffer).  Keep trying. */
                status = NOTOK;
            }
        }
    } else {
        status = NOTOK;
    }

    if (ct->c_fp) {
        fclose (ct->c_fp);
        ct->c_fp = NULL;
    }

    if (status == OK) {
        *part_boundary = end_boundary;
    } else {
        *part_boundary = NULL;
        free (end_boundary);
    }

    return status;
}


/*
 * Open and copy ct->c_file to file, replacing the multipart boundary.
 */
static int
replace_boundary (CT ct, char *file, char *boundary)
{
    FILE *fpin, *fpout;
    int compnum, state;
    char buf[NMH_BUFSIZ], name[NAMESZ];
    char *np, *vp;
    m_getfld_state_t gstate;
    int status = OK;

    if (ct->c_file == NULL) {
        inform("missing input filename");
        return NOTOK;
    }

    if ((fpin = fopen (ct->c_file, "r")) == NULL) {
        advise (ct->c_file, "unable to open for reading");
        return NOTOK;
    }

    if ((fpout = fopen (file, "w")) == NULL) {
        fclose (fpin);
        advise (file, "unable to open for writing");
        return NOTOK;
    }

    gstate = m_getfld_state_init(fpin);
    for (compnum = 1;;) {
        int bufsz = (int) sizeof buf;

        switch (state = m_getfld2(&gstate, name, buf, &bufsz)) {
        case FLD:
        case FLDPLUS:
            compnum++;

            /* get copies of the buffers */
            np = mh_xstrdup (name);
            vp = mh_xstrdup (buf);

            /* if necessary, get rest of field */
            while (state == FLDPLUS) {
                bufsz = sizeof buf;
                state = m_getfld2(&gstate, name, buf, &bufsz);
                vp = add (buf, vp);     /* add to previous value */
            }

            if (strcasecmp (TYPE_FIELD, np)) {
                fprintf (fpout, "%s:%s", np, vp);
            } else {
                char *new_ctline, *new_params;

                replace_param(&ct->c_ctinfo.ci_first_pm,
                              &ct->c_ctinfo.ci_last_pm, "boundary",
                              boundary, 0);

                new_ctline = concat(" ", ct->c_ctinfo.ci_type, "/",
                                    ct->c_ctinfo.ci_subtype, NULL);
                new_params = output_params(LEN(TYPE_FIELD) +
                                           strlen(new_ctline) + 1,
                                           ct->c_ctinfo.ci_first_pm, NULL, 0);
                fprintf (fpout, "%s:%s%s\n", np, new_ctline,
                         FENDNULL(new_params));
                free(new_ctline);
                free(new_params);
            }

            free (vp);
            free (np);

            continue;

        case BODY:
            putc('\n', fpout);
            /* buf will have a terminating NULL, skip it. */
            if ((int) fwrite (buf, 1, bufsz-1, fpout) < bufsz-1) {
                advise (file, "fwrite");
            }
            continue;

        case FILEEOF:
            break;

        case LENERR:
        case FMTERR:
            inform("message format error in component #%d", compnum);
            status = NOTOK;
            break;

        default:
            inform("getfld() returned %d", state);
            status = NOTOK;
            break;
        }

        break;
    }

    m_getfld_state_destroy (&gstate);
    fclose (fpout);
    fclose (fpin);

    return status;
}


/*
 * Fix Content-Type header to reflect the content of its part.
 */
static int
fix_types (CT ct, svector_t fixtypes, int *message_mods)
{
    int status = OK;

    switch (ct->c_type) {
    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) ct->c_ctparams;
        struct part *part;

        for (part = m->mp_parts; status == OK  &&  part; part = part->mp_next) {
            status = fix_types (part->mp_part, fixtypes, message_mods);
        }
        break;
    }

    case CT_MESSAGE:
        if (ct->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) ct->c_ctparams;

            status = fix_types (e->eb_content, fixtypes, message_mods);
        }
        break;

    default: {
        char **typep, *type;

        if (ct->c_ctinfo.ci_type  &&  ct->c_ctinfo.ci_subtype) {
            for (typep = svector_strs (fixtypes);
                 typep && (type = *typep);
                 ++typep) {
                char *type_subtype =
                    concat (ct->c_ctinfo.ci_type, "/", ct->c_ctinfo.ci_subtype,
                            NULL);

                if (! strcasecmp (type, type_subtype)  &&
                    decode_part (ct) == OK  &&
                    ct->c_cefile.ce_file != NULL) {
                    char *ct_type_subtype = mime_type (ct->c_cefile.ce_file);
                    char *cp;

                    if ((cp = strchr (ct_type_subtype, ';'))) {
                        /* Truncate to remove any parameter list from
                           mime_type () result. */
                        *cp = '\0';
                    }

                    if (strcasecmp (type, ct_type_subtype)) {
                        char *ct_type, *ct_subtype;
                        HF hf;

                        /* The Content-Type header does not match the
                           content, so update these struct Content
                           fields to match:
                           * c_type, c_subtype
                           * c_ctinfo.ci_type, c_ctinfo.ci_subtype
                           * c_ctline
                           */
                        /* Extract type and subtype from type/subtype. */
                        ct_type = mh_xstrdup(ct_type_subtype);
                        if ((cp = strchr (ct_type, '/'))) {
                            *cp = '\0';
                            ct_subtype = mh_xstrdup(++cp);
                        } else {
                            inform("missing / in MIME type of %s %s",
                                    ct->c_file, ct->c_partno);
                            free (ct_type);
                            return NOTOK;
                        }

                        ct->c_type = ct_str_type (ct_type);
                        ct->c_subtype = ct_str_subtype (ct->c_type, ct_subtype);

                        free (ct->c_ctinfo.ci_type);
                        ct->c_ctinfo.ci_type = ct_type;
                        free (ct->c_ctinfo.ci_subtype);
                        ct->c_ctinfo.ci_subtype = ct_subtype;
                        if (! replace_substring (&ct->c_ctline, type,
                                                 ct_type_subtype)) {
                            inform("did not find %s in %s",
                                    type, ct->c_ctline);
                        }

                        /* Update Content-Type header field. */
                        for (hf = ct->c_first_hf; hf; hf = hf->next) {
                            if (! strcasecmp (TYPE_FIELD, hf->name)) {
                                if (replace_substring (&hf->value, type,
                                                       ct_type_subtype)) {
                                    ++*message_mods;
                                    if (verbosw) {
                                        report (NULL, ct->c_partno, ct->c_file,
                                                "change Content-Type in header "
                                                "from %s to %s",
                                                type, ct_type_subtype);
                                    }
                                    break;
                                }
                                char *hf_value = cpytrim (hf->value);
                                inform("did not find %s in %s", type, hf_value);
                                free (hf_value);
                            }
                        }
                    }
                    free (ct_type_subtype);
                }
                free (type_subtype);
            }
        }
    }}

    return status;
}


/*
 * Replace a substring, allocating space to hold the new one.
 */
char *
replace_substring (char **str, const char *old, const char *new)
{
    char *cp;

    if ((cp = strstr (*str, old))) {
        char *remainder = cp + strlen (old);
        char *prefix, *new_str;

        if (cp - *str) {
            prefix = mh_xstrdup(*str);
            *(prefix + (cp - *str)) = '\0';
            new_str = concat (prefix, new, remainder, NULL);
            free (prefix);
        } else {
            new_str = concat (new, remainder, NULL);
        }

        free (*str);

        return *str = new_str;
    }

    return NULL;
}


/*
 * Remove a name=value parameter, given just its name, from a header value.
 */
char *
remove_parameter (char *str, const char *name)
{
    /* It looks to me, based on the BNF in RFC 2045, than there can't
       be whitespace between the parameter name and the "=", or
       between the "=" and the parameter value. */
    char *param_name = concat (name, "=", NULL);
    char *cp;

    if ((cp = strstr (str, param_name))) {
        char *start, *end;
        size_t count = 1;

        /* Remove any leading spaces, before the parameter name. */
        for (start = cp;
             start > str && isspace ((unsigned char) *(start-1));
             --start) {
            continue;
        }
        /* Remove a leading semicolon. */
        if (start > str  &&  *(start-1) == ';') { --start; }

        end = cp + strlen (name) + 1;
        if (*end == '"') {
            /* Skip past the quoted value, and then the final quote. */
            for (++end ; *end  &&  *end != '"'; ++end) { continue; }
            ++end;
        } else {
            /* Skip past the value. */
            for (++end ; *end  &&  ! isspace ((unsigned char) *end); ++end) {}
        }

        /* Count how many characters need to be moved.  Include
           trailing null, which is accounted for by the
           initialization of count to 1. */
        for (cp = end; *cp; ++cp) { ++count; }
        (void) memmove (start, end, count);
    }

    free (param_name);

    return str;
}


/*
 * Fix Content-Transfer-Encoding of composite,, e.g., message or multipart, part.
 * According to RFC 2045 Sec. 6.4, it must be 7bit, 8bit, or binary.  Set it to
 * 8 bit.
 */
static int
fix_composite_cte (CT ct, int *message_mods)
{
    int status = OK;

    if (ct->c_type == CT_MESSAGE  ||  ct->c_type == CT_MULTIPART) {
        if (ct->c_encoding != CE_7BIT  &&  ct->c_encoding != CE_8BIT  &&
            ct->c_encoding != CE_BINARY) {
            HF hf;

            for (hf = ct->c_first_hf; hf; hf = hf->next) {
                char *name = hf->name;
                for (; isspace((unsigned char)*name); ++name) {
                    continue;
                }

                if (! strncasecmp (name, ENCODING_FIELD,
                                   LEN(ENCODING_FIELD))) {
                    char *prefix = "Nmh-REPLACED-INVALID-";
                    HF h;

                    NEW(h);
                    h->name = mh_xstrdup (hf->name);
                    h->next = hf->next;
                    hf->next = h;

                    /* Retain old header but prefix its name. */
                    free (hf->name);
                    hf->name = concat (prefix, h->name, NULL);

                    ++*message_mods;
                    if (verbosw) {
                        char *encoding = cpytrim (hf->value);
                        report (NULL, ct->c_partno, ct->c_file,
                                "replace Content-Transfer-Encoding of %s "
                                "with 8 bit", encoding);
                        free (encoding);
                    }

                    h->value = mh_xstrdup (" 8bit\n");

                    /* Don't need to warn for multiple C-T-E header
                       fields, parse_mime() already does that.  But
                       if there are any, fix them all as necessary. */
                    hf = h;
                }
            }

            set_ce (ct, CE_8BIT);
        }

        if (ct->c_type == CT_MULTIPART) {
            struct multipart *m;
            struct part *part;

            m = (struct multipart *) ct->c_ctparams;
            for (part = m->mp_parts; part; part = part->mp_next) {
                if (fix_composite_cte (part->mp_part, message_mods) != OK) {
                    status = NOTOK;
                    break;
                }
            }
        }
    }

    return status;
}


/*
 * Set content encoding.
 */
static int
set_ce (CT ct, int encoding)
{
    const char *ce = ce_str (encoding);
    const struct str2init *ctinit = get_ce_method (ce);

    if (ctinit) {
        char *cte = concat (" ", ce, "\n", NULL);
        bool found_cte = false;
        HF hf;
        /* Decoded contents might be in ct->c_cefile.ce_file, if the
           caller is decode_text_parts ().  Save because we'll
           overwrite below. */
        struct cefile decoded_content_info = ct->c_cefile;

        ct->c_encoding = encoding;

        ct->c_ctinitfnx = ctinit->si_init;
        /* This will assign ct->c_cefile with an all-0 struct, which
           is what we want. */
        (*ctinit->si_init) (ct);
        /* After returning, the caller should set
           ct->c_cefile.ce_file to the name of the file containing
           the contents. */

        if (ct->c_ceclosefnx) {
            (*ct->c_ceclosefnx) (ct);
        }

        /* Restore the cefile. */
        ct->c_cefile = decoded_content_info;

        /* Update/add Content-Transfer-Encoding header field. */
        for (hf = ct->c_first_hf; hf; hf = hf->next) {
            if (! strcasecmp (ENCODING_FIELD, hf->name)) {
                found_cte = true;
                free (hf->value);
                hf->value = cte;
            }
        }
        if (! found_cte) {
            add_header (ct, mh_xstrdup (ENCODING_FIELD), cte);
        }

        /* Update c_celine.  It's used only by mhlist -debug. */
        free (ct->c_celine);
        ct->c_celine = mh_xstrdup (cte);

        return OK;
    }

    return NOTOK;
}


/*
 * Make sure each text part has a corresponding text/plain part.
 */
static int
ensure_text_plain (CT *ct, CT parent, int *message_mods, const text_properties *text_props)
{
    int status = OK;

    switch ((*ct)->c_type) {
    case CT_TEXT: {
        /* Nothing to do for text/plain. */
        if ((*ct)->c_subtype == TEXT_PLAIN) { return OK; }

        if (parent  &&  parent->c_type == CT_MULTIPART  &&
            parent->c_subtype == MULTI_ALTERNATE) {
            int new_subpart_number = 1;
            int has_text_plain =
                find_textplain_sibling (parent, text_props->replacetextplain,
                                        &new_subpart_number);

            if (! has_text_plain) {
                /* Parent is a multipart/alternative.  Insert a new
                   text/plain subpart. */
                const int inserted =
                    insert_new_text_plain_part (*ct, new_subpart_number,
                                                parent, text_props);
                if (inserted) {
                    ++*message_mods;
                    if (verbosw) {
                        report (NULL, parent->c_partno, parent->c_file,
                                "insert text/plain part");
                    }
                } else {
                    status = NOTOK;
                }
            }
        } else if (parent  &&  parent->c_type == CT_MULTIPART  &&
            parent->c_subtype == MULTI_RELATED) {
            char *type_subtype =
                concat ((*ct)->c_ctinfo.ci_type, "/",
                        (*ct)->c_ctinfo.ci_subtype, NULL);
            const char *parent_type =
                get_param (parent->c_ctinfo.ci_first_pm, "type", '?', 1);
            int new_subpart_number = 1;
            int has_text_plain = 0;

            /* Have to do string comparison on the subtype because we
               don't enumerate all of them in c_subtype values.
               parent_type will be NULL if the multipart/related part
               doesn't have a type parameter.  The type parameter must
               be specified according to RFC 2387 Sec. 3.1 but not all
               messages comply. */
            if (parent_type  &&  strcasecmp (type_subtype, parent_type) == 0) {
                /* The type of this part matches the root type of the
                   parent multipart/related.  Look to see if there's
                   text/plain sibling. */
                has_text_plain =
                    find_textplain_sibling (parent, text_props->replacetextplain,
                                            &new_subpart_number);
            }

            free (type_subtype);

            if (! has_text_plain) {
                struct multipart *mp = (struct multipart *) parent->c_ctparams;
                struct part *part;
                int siblings = 0;

                for (part = mp->mp_parts; part; part = part->mp_next) {
                    if (*ct != part->mp_part) {
                        ++siblings;
                    }
                }

                if (siblings) {
                    /* Parent is a multipart/related.  Insert a new
                       text/plain subpart in a new multipart/alternative. */
                    if (insert_into_new_mp_alt (ct, message_mods, text_props)) {
                        /* Not an error if text/plain couldn't be added. */
                    }
                } else {
                    /* There are no siblings, so insert a new text/plain
                       subpart, and change the parent type from
                       multipart/related to multipart/alternative. */
                    const int inserted =
                        insert_new_text_plain_part (*ct, new_subpart_number,
                                                    parent, text_props);

                    if (inserted) {
                        HF hf;

                        parent->c_subtype = MULTI_ALTERNATE;
                        free (parent->c_ctinfo.ci_subtype);
                        parent->c_ctinfo.ci_subtype = mh_xstrdup("alternative");
                        if (! replace_substring (&parent->c_ctline, "/related",
                                                 "/alternative")) {
                            inform("did not find multipart/related in %s",
                                parent->c_ctline);
                        }

                        /* Update Content-Type header field. */
                        for (hf = parent->c_first_hf; hf; hf = hf->next) {
                            if (! strcasecmp (TYPE_FIELD, hf->name)) {
                                if (replace_substring (&hf->value, "/related",
                                                       "/alternative")) {
                                    ++*message_mods;
                                    if (verbosw) {
                                        report (NULL, parent->c_partno,
                                                parent->c_file,
                                                "insert text/plain part");
                                    }

                                    /* Remove, e.g., type="text/html" from
                                       multipart/alternative. */
                                    remove_parameter (hf->value, "type");
                                    break;
                                }
                                char *hf_value = cpytrim (hf->value);
                                inform("did not find multipart/"
                                    "related in header %s", hf_value);
                                free (hf_value);
                            }
                        }
                    } else {
                        /* Not an error if text/plain couldn't be inserted. */
                    }
                }
            }
        } else {
            if (insert_into_new_mp_alt (ct, message_mods, text_props)) {
                status = NOTOK;
            }
        }
        break;
    }

    case CT_MULTIPART: {
        struct multipart *mp = (struct multipart *) (*ct)->c_ctparams;
        struct part *part;

        for (part = mp->mp_parts; status == OK && part; part = part->mp_next) {
            if ((*ct)->c_type == CT_MULTIPART) {
                status = ensure_text_plain (&part->mp_part, *ct, message_mods,
                                            text_props);
            }
        }
        break;
    }

    case CT_MESSAGE:
        if ((*ct)->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) (*ct)->c_ctparams;

            status = ensure_text_plain (&e->eb_content, *ct, message_mods,
                                        text_props);
        }
        break;
    }

    return status;
}


/*
 * See if there is a sibling text/plain, and return its subpart number.
 */
static int
find_textplain_sibling (CT parent, int replacetextplain,
                        int *new_subpart_number)
{
    struct multipart *mp = (struct multipart *) parent->c_ctparams;
    struct part *part, *prev;
    bool has_text_plain = false;

    for (prev = part = mp->mp_parts; part; part = part->mp_next) {
        ++*new_subpart_number;
        if (part->mp_part->c_type == CT_TEXT  &&
            part->mp_part->c_subtype == TEXT_PLAIN) {
            if (replacetextplain) {
                struct part *old_part;
                if (part == mp->mp_parts) {
                    old_part = mp->mp_parts;
                    mp->mp_parts = part->mp_next;
                } else {
                    old_part = prev->mp_next;
                    prev->mp_next = part->mp_next;
                }
                if (verbosw) {
                    report (NULL, parent->c_partno, parent->c_file,
                            "remove text/plain part %s",
                            old_part->mp_part->c_partno);
                }
                free_content (old_part->mp_part);
                free (old_part);
            } else {
                has_text_plain = true;
            }
            break;
        }
        prev = part;
    }

    return has_text_plain;
}


/*
 * Insert a new text/plain part in a multipart part.
 */
static int
insert_new_text_plain_part (CT ct, int new_subpart_number, CT parent,
                            const text_properties *text_props)
{
    struct multipart *mp = (struct multipart *) parent->c_ctparams;
    struct part *new_part;

    NEW(new_part);
    if ((new_part->mp_part = build_text_plain_part (ct, text_props))) {
        char buffer[16];
        snprintf (buffer, sizeof buffer, "%d", new_subpart_number);

        new_part->mp_next = mp->mp_parts;
        mp->mp_parts = new_part;
        new_part->mp_part->c_partno =
            concat (parent->c_partno ? parent->c_partno : "1", ".",
                    buffer, NULL);

        return 1;
    }

    free_content (new_part->mp_part);
    free (new_part);

    return 0;
}


/*
 * Create a text/plain part to go along with non-plain sibling part.
 */
static CT
build_text_plain_part (CT encoded_part, const text_properties *text_props)
{
    CT tp_part = divide_part (encoded_part);
    char *tmp_plain_file = NULL;

    if (decode_part (tp_part) == OK) {
        /* Now, tp_part->c_cefile.ce_file is the name of the tmp file that
           contains the decoded contents.  And the decoding function, such
           as openQuoted, will have set ...->ce_unlink to 1 so that it will
           be unlinked by free_content (). */
        char *tempfile;

        /* This m_mktemp2() call closes the temp file. */
        if ((tempfile = m_mktemp2 (NULL, invo_name, NULL, NULL)) == NULL) {
            inform("unable to create temporary file in %s", get_temp_dir());
        } else {
            tmp_plain_file = mh_xstrdup (tempfile);
            if (reformat_part (tp_part, tmp_plain_file,
                               tp_part->c_ctinfo.ci_type,
                               tp_part->c_ctinfo.ci_subtype,
                               tp_part->c_type,
                               text_props) == OK) {
                return tp_part;
            }
        }
    }

    free_content (tp_part);
    if (tmp_plain_file) { (void) m_unlink (tmp_plain_file); }
    free (tmp_plain_file);

    return NULL;
}


/*
 * Slip new text/plain part into a new multipart/alternative.
 */
static int
insert_into_new_mp_alt (CT *ct, int *message_mods, const text_properties *text_props)
{
    /* The following will call decode_part().  */
    CT tp_part = build_text_plain_part (*ct, text_props);
    int status = OK;

    if (tp_part) {
        CT mp_alt = build_multipart (*ct, tp_part, CT_MULTIPART,
                                     MULTI_ALTERNATE);
        if (mp_alt) {
            struct multipart *mp = (struct multipart *) mp_alt->c_ctparams;

            if (mp  &&  mp->mp_parts) {
                mp->mp_parts->mp_part = tp_part;
                /* Make the new multipart/alternative the parent. */
                *ct = mp_alt;

                ++*message_mods;
                if (verbosw) {
                    report (NULL, (*ct)->c_partno, (*ct)->c_file,
                            "insert text/plain part");
                }
            } else {
                free_content (tp_part);
                free_content (mp_alt);
                status = NOTOK;
            }
        } else {
            status = NOTOK;
        }
    } else {
        /* Not an error if text/plain couldn't be built. */
    }

    return status;
}


/*
 * Slip new text/plain part into a new multipart/mixed.
 */
static int
insert_into_new_mp_mixed (CT *ct, const char *content, int *message_mods)
{
    CT main_part = divide_part (*ct);
    const char *reason = NULL;
    const int encoding = content_encoding (main_part, &reason);
    int status = OK;

    if (set_ct_type(main_part, (*ct)->c_type, (*ct)->c_subtype,
                    main_part->c_encoding, NULL) != OK) {
        inform("failed to set Content-Type of main part");
        return NOTOK;
    }
    if (set_ct_type(*ct, (*ct)->c_type, (*ct)->c_subtype, encoding, NULL) != OK) {
        inform("failed to set Content-Type of new part");
        return NOTOK;
    }

    if (main_part) {
        /* Load remainder into the new part. */
        CE cefile = &(*ct)->c_cefile;
        CT mp_alt;

        cefile->ce_file =
            mh_xstrdup(m_mktemp2 (NULL, invo_name, NULL, &cefile->ce_fp));
        if (cefile->ce_file == NULL) {
            die("unable to create temporary file in %s", get_temp_dir());
        }
        cefile->ce_unlink = 1;
        fprintf (cefile->ce_fp, "%s", content);

        /* Put both parts into a new multipart. */
        mp_alt = build_multipart (*ct, main_part, CT_MULTIPART, MULTI_MIXED);
        if (mp_alt) {
            struct multipart *mp = (struct multipart *) mp_alt->c_ctparams;

            /* So fix_composite_cte doesn't try to overwrite the encoding.  If
               the content needs to be decoded, c_encoding will be properly
               set. */
            mp_alt->c_encoding = encoding;

            if (mp  &&  mp->mp_parts) {
                mp->mp_parts->mp_part = main_part;
                /* Make the new multipart/alternative the parent. */
                *ct = mp_alt;

                ++*message_mods;
                if (verbosw) {
                    report (NULL, (*ct)->c_partno, (*ct)->c_file,
                            "insert text/plain part");
                }
            } else {
                free_content (main_part);
                free_content (mp_alt);
                status = NOTOK;
            }
        } else {
            inform("failed to build multipart/alternate");
            status = NOTOK;
        }
    } else {
        /* Should never happen. */
        inform("failed to insert new text part into multipart/related");
        status = NOTOK;
    }

    return status;
}


/*
 * Clone a MIME part.
 */
static CT
divide_part (CT ct)
{
    CT new_part;

    NEW0(new_part);
    /* Just copy over what is needed for decoding.  c_vrsn and
       c_celine aren't necessary. */
    new_part->c_file = mh_xstrdup (ct->c_file);
    new_part->c_begin = ct->c_begin;
    new_part->c_end = ct->c_end;
    copy_ctinfo (&new_part->c_ctinfo, &ct->c_ctinfo);
    new_part->c_type = ct->c_type;
    new_part->c_cefile = ct->c_cefile;
    new_part->c_encoding = ct->c_encoding;
    new_part->c_ctinitfnx = ct->c_ctinitfnx;
    new_part->c_ceopenfnx = ct->c_ceopenfnx;
    new_part->c_ceclosefnx = ct->c_ceclosefnx;
    new_part->c_cesizefnx = ct->c_cesizefnx;

    /* c_ctline is used by reformat_part(), so it can preserve
       anything after the type/subtype. */
    new_part->c_ctline = mh_xstrdup (ct->c_ctline);

    return new_part;
}


/*
 * Copy the content info from one part to another.
 */
static void
copy_ctinfo (CI dest, CI src)
{
    PM s_pm, d_pm;

    dest->ci_type = src->ci_type ? mh_xstrdup (src->ci_type) : NULL;
    dest->ci_subtype = src->ci_subtype ? mh_xstrdup (src->ci_subtype) : NULL;

    for (s_pm = src->ci_first_pm; s_pm; s_pm = s_pm->pm_next) {
        d_pm = add_param(&dest->ci_first_pm, &dest->ci_last_pm, s_pm->pm_name,
                         s_pm->pm_value, 0);
        if (s_pm->pm_charset) {
            d_pm->pm_charset = mh_xstrdup(s_pm->pm_charset);
        }
        if (s_pm->pm_lang) {
            d_pm->pm_lang = mh_xstrdup(s_pm->pm_lang);
        }
    }

    dest->ci_comment = src->ci_comment ? mh_xstrdup (src->ci_comment) : NULL;
    dest->ci_magic = src->ci_magic ? mh_xstrdup (src->ci_magic) : NULL;
}


/*
 * Decode content.
 */
static int
decode_part (CT ct)
{
    char *tempfile, *tmp_decoded;
    FILE *file;
    int status;

    if ((tempfile = m_mktemp2 (NULL, invo_name, NULL, &file)) == NULL) {
        die("unable to create temporary file in %s", get_temp_dir());
    }
    tmp_decoded = mh_xstrdup (tempfile);
    /* The following call will load ct->c_cefile.ce_file with the tmp
       filename of the decoded content.  tmp_decoded will contain the
       encoded output, get rid of that. */
    status = output_message_fp (ct, file, tmp_decoded);
    (void) m_unlink (tmp_decoded);
    free (tmp_decoded);
    if (fclose (file)) {
        inform("unable to close temporary file %s, continuing...", tempfile);
    }

    return status;
}


/*
 * If base64-encoded content has a text trailer, return the location, relative
 * to c->c_begin, where the valid base64 ends.  And return the trailer in the
 * addresses pointed to by remainderp.  The caller is responsible for
 * deallocating that.  If no text trailer, return ct->c_end - ct->c_begin and
 * leave remainderp unchanged.
 */
static size_t
get_valid_base64 (CT ct, char **remainderp) {
    const size_t len = ct->c_end - ct->c_begin;
    char *buf, format[sizeof "%18446744073709551615c"];
    size_t pos;
    int fd;

    if (! ct->c_fp  &&  ((ct->c_fp = fopen (ct->c_file, "r")) == NULL)) {
        advise (ct->c_file, "unable to open for reading");
        return NOTOK;
    }
    if ((fd = fileno (ct->c_fp)) == -1  ||
        lseek (fd, ct->c_begin, SEEK_SET) == (off_t) -1) {
        advise (ct->c_file, "unable to seek in");
        return NOTOK;
    }
    buf = mh_xmalloc(len + 1);
    snprintf(format, sizeof format, "%%%zuc", len);
    if (fscanf(ct->c_fp, format, buf) == EOF) {
        advise (ct->c_file, "unable to read");
        return NOTOK;
    }
    buf[len] = '\0';

    pos = find_invalid_base64_pos(buf);

    if (ct->c_begin + pos < (size_t) ct->c_end) {
        *remainderp = mh_xstrdup(&buf[pos]);
    } else {
        pos = ct->c_end - ct->c_begin;
    }
    free(buf);

    return pos;
}


/*
 * Find position in byte string of invalid base64 code.  Skip individual
 * invalid characters because RFC 2045 Sec 6.8 says they should be ignored.
 * The motivating use case is a text footer that was mistakenly applied to
 * base64 content.  Therefore, if any of these is found, return the position
 * of:
 * 1. The byte (or end) after one or two consecutive pad ('=') bytes.
 * 2. The first of a pair of invalid base64 bytes.
 *
 * If the base64 code is valid, return the position of the null terminator.
 *
 * encoded      - the base64-encoded string
 */
static size_t
find_invalid_base64_pos (const char *encoded) {
    const char *cp;
    size_t pos;
    bool found_pad = false;
    unsigned int found_invalid = 0;

    for (cp = encoded, pos = 0;
         *cp && ! found_pad && found_invalid < 2;
         ++cp, ++pos) {
        if (isspace ((unsigned char) *cp) ||
            isalnum ((unsigned char) *cp) ||
            *cp == '+' || *cp == '/' || *cp == '=') {
            /* Valid base64 byte. */
            if (*cp == '=') {
                /* "evidence that the end of the data has been reached"
                   according to RFC 2045 */
                found_pad = true;
            }
            /* Require consecutive invalid bytes.  Let decodeBase64() handle
               individual ones. */
            found_invalid = 0;
        } else {
            ++found_invalid;
        }
    }

    if (found_pad  &&  *cp  &&  *cp == '=') {
        /* Skip over last in pair of ==. */
        ++cp, ++pos;
    } else if (found_invalid == 2) {
        /* If a pair of consecutive invalid bytes, back up to first one. */
        --cp, --pos;
        --cp, --pos;
    }

    /* Skip over any trailing whitespace. */
    while (*cp  &&  isspace((unsigned char) *cp)) {
        ++cp, ++pos;
    }

    return pos;
}


/*
 * Check for valid base64 encoding, and "fix" if invalid.
 */
static int
check_base64_encoding (CT *ctp)
{
    char *remainder = NULL;
    int status = OK;

    /* If there's a footer after base64 content, set c_end to before it, and
       store the footer in remainder. */
    (*ctp)->c_end = (*ctp)->c_begin + get_valid_base64(*ctp, &remainder);

    if (remainder != NULL) {
        /* Move ct to a subpart of a new multipart/related, and add the
           remainder as a new text/plain subpart of it. */
        int ignore_message_mods = 0;

        status = insert_into_new_mp_mixed(ctp, remainder, &ignore_message_mods);
        free(remainder);
    }

    return status;
}


/*
 * Reformat content as plain text.
 * Some of the arguments aren't really needed now, but maybe will be in the
 * future for other than text types.
 */
static int
reformat_part (CT ct, char *file, char *type, char *subtype, int c_type,
               const text_properties *text_props)
{
    int output_subtype, output_encoding;
    char *charset = NULL;
    char *cp, *cf;
    int status;

    /* Hacky:  this redirects the output from whatever command is used
       to show the part to a file.  So, the user can't have any output
       redirection in that command.
       Could show_multi() in mhshowsbr.c avoid this? */

    /* Check for invo_name-format-type/subtype. */
    if ((cf = context_find_by_type ("format", type, subtype)) == NULL) {
        if (verbosw) {
            inform("Don't know how to convert %s, there is no "
                    "%s-format-%s/%s profile entry",
                    ct->c_file, invo_name, type, subtype);
        }
        return NOTOK;
    }
    if (strchr (cf, '>')) {
        inform("'>' prohibited in \"%s\",\nplease fix your "
                "%s-format-%s/%s profile entry", cf, invo_name, type,
                FENDNULL(subtype));

        return NOTOK;
    }

    cp = concat (cf, " >", file, NULL);
    status = show_content_aux (ct, 0, cp, NULL, NULL);
    free (cp);

    if (status == OK) {
        const char *reason = NULL;

        /* Update charset based on file contents or -textcharset value. */
        charset = encoding(file);
        if (charset == NULL) {
            charset = text_props && text_props->textcharset
                ? mh_xstrdup (text_props->textcharset) : NULL;
        }
        if (charset == NULL) {
            charset = mh_xstrdup(get_charset());
            advise(NULL, "Assuming %s for new text/plain part, "
                   "use -textcharset to override", charset);
        }
        /* This is necessary to update the charset in the part headers. */
        replace_param(&ct->c_ctinfo.ci_first_pm,
                      &ct->c_ctinfo.ci_last_pm, "charset",
                      charset, 0);
        /* This is necessary to output the correct charset. */
        add_header (ct, mh_xstrdup (TYPE_FIELD),
                    concat (ct->c_ctline, "\n", NULL));

        /* Unlink decoded content tmp file and free its filename to avoid
           leaks.  The file stream should already have been closed. */
        if (ct->c_cefile.ce_unlink) {
            (void) m_unlink (ct->c_cefile.ce_file);
            free (ct->c_cefile.ce_file);
            ct->c_cefile.ce_file = NULL;
            ct->c_cefile.ce_unlink = 0;
        }

        if (c_type == CT_TEXT) {
            output_subtype = TEXT_PLAIN;
        } else {
            /* Set subtype to 0, which is always an UNKNOWN subtype. */
            output_subtype = 0;
        }

        /* Wrap charset in double quotes if it's not already. */
        if (charset  &&  charset[0] != '"') {
            char *temp = charset;
            charset = concat ("\"", charset, "\"", NULL);
            free (temp);
        }

        ct->c_cefile.ce_file = file;
        ct->c_cefile.ce_unlink = 1;
        output_encoding = content_encoding (ct, &reason);

        if ((status = set_ct_type (ct, c_type, output_subtype, output_encoding,
                                   charset)) != OK) {
            ct->c_cefile.ce_unlink = 0;
        }
    } else {
        ct->c_cefile.ce_unlink = 0;
    }
    free (charset);

    return status;
}


/*
 * Create and fill in a multipart part.
 */
static CT
build_multipart (CT first_part, CT new_part, int type, int subtype)
{
    char *boundary_prefix = "----=_nmh-multipart";
    static unsigned int bp_uses = 0;
    char bp_uses_buf[16];
    char *boundary;
    char *boundary_indicator = "; boundary=";
    char *typename, *subtypename, *name;
    CT ct;
    struct part *p;
    struct multipart *m;
    const struct str2init *ctinit;

    NEW0(ct);

    if (bp_uses > 0) {
        snprintf(bp_uses_buf, sizeof bp_uses_buf - 1, "-%u", bp_uses++);
    } else {
        bp_uses_buf[0] = '\0';
    }
    boundary =
        concat (boundary_prefix, bp_uses_buf, first_part->c_partno, NULL);

    /* Set up the multipart part.  These fields of *ct were
       initialized to 0 by mh_xcalloc():
       c_fp, c_unlink, c_begin, c_end,
       c_vrsn, c_ctline, c_celine,
       c_id, c_descr, c_dispo, c_partno,
       c_ctinfo.ci_comment, c_ctinfo.ci_magic,
       c_cefile, c_encoding,
       c_digested, c_digest[16], c_ctexbody,
       c_ctinitfnx, c_ceopenfnx, c_ceclosefnx, c_cesizefnx,
       c_umask, c_rfc934,
       c_showproc, c_termproc, c_storeproc, c_storage, c_folder
    */

    ct->c_file = mh_xstrdup (first_part->c_file);
    ct->c_type = type;
    ct->c_subtype = subtype;

    ctinit = get_ct_init (ct->c_type);

    typename = ct_type_str (type);
    subtypename = ct_subtype_str (type, subtype);

    {
        int serial = 0;
        int found_boundary = 1;

        while (found_boundary  &&  serial < 1000000) {
            found_boundary = 0;

            /* Ensure that the boundary doesn't appear in the decoded
               content. */
            if (new_part->c_cefile.ce_file) {
                if ((found_boundary =
                     boundary_in_content (&new_part->c_cefile.ce_fp,
                                          new_part->c_cefile.ce_file,
                                          boundary)) == NOTOK) {
                    goto return_null;
                }
            }

            /* Ensure that the boundary doesn't appear in the encoded
               content. */
            if (! found_boundary  &&  new_part->c_file) {
                if ((found_boundary =
                     boundary_in_content (&new_part->c_fp,
                                          new_part->c_file,
                                          boundary)) == NOTOK) {
                    goto return_null;
                }
            }

            if (found_boundary) {
                /* Try a slightly different boundary. */
                char buffer2[16];

                free (boundary);
                ++serial;
                snprintf (buffer2, sizeof buffer2, "%d", serial);
                boundary =
                    concat (boundary_prefix,
                            FENDNULL(first_part->c_partno),
                            "-", buffer2,  NULL);
            }
        }

        if (found_boundary) {
            inform("giving up trying to find a unique boundary");
            goto return_null;
        }
    }

    name = concat (" ", typename, "/", subtypename, boundary_indicator, "\"",
                   boundary, "\"", NULL);

    /* Load c_first_hf and c_last_hf. */
    transfer_noncontent_headers (first_part, ct);
    add_header (ct, mh_xstrdup (TYPE_FIELD), concat (name, "\n", NULL));
    free (name);

    /* Load c_partno. */
    if (first_part->c_partno) {
        ct->c_partno = mh_xstrdup (first_part->c_partno);
        free (first_part->c_partno);
        first_part->c_partno = concat (ct->c_partno, ".1", NULL);
        new_part->c_partno = concat (ct->c_partno, ".2", NULL);
    } else {
        first_part->c_partno = mh_xstrdup ("1");
        new_part->c_partno = mh_xstrdup ("2");
    }

    if (ctinit) {
        ct->c_ctinfo.ci_type = mh_xstrdup (typename);
        ct->c_ctinfo.ci_subtype = mh_xstrdup (subtypename);
    }

    add_param(&ct->c_ctinfo.ci_first_pm, &ct->c_ctinfo.ci_last_pm,
              "boundary", boundary, 0);

    NEW(p);
    NEW(p->mp_next);
    p->mp_next->mp_next = NULL;
    p->mp_next->mp_part = first_part;

    NEW0(m);
    m->mp_start = concat (boundary, "\n", NULL);
    m->mp_stop = concat (boundary, "--\n", NULL);
    m->mp_parts = p;
    ct->c_ctparams = m;

    free (boundary);

    return ct;

return_null:
    free_content(ct);
    free(boundary);
    return NULL;
}


/*
 * Check that the boundary does not appear in the content.
 */
static int
boundary_in_content (FILE **fp, char *file, const char *boundary)
{
    char buffer[NMH_BUFSIZ];
    size_t bytes_read;
    bool found_boundary = false;

    /* free_content() will close *fp if we fopen it here. */
    if (! *fp  &&  (*fp = fopen (file, "r")) == NULL) {
        advise (file, "unable to open %s for reading", file);
        return NOTOK;
    }

    fseeko (*fp, 0L, SEEK_SET);
    while ((bytes_read = fread (buffer, 1, sizeof buffer, *fp)) > 0) {
        if (find_str (buffer, bytes_read, boundary)) {
            found_boundary = true;
            break;
        }
    }

    return found_boundary;
}


/*
 * Skip all Content- headers.
 */
static void
transfer_noncontent_headers (CT old, CT new)
{
    HF hp, hp_prev;

    hp_prev = hp = old->c_first_hf;
    while (hp) {
        HF next = hp->next;

        if (strncasecmp (XXX_FIELD_PRF, hp->name, LEN(XXX_FIELD_PRF))) {
            if (hp == old->c_last_hf) {
                if (hp == old->c_first_hf) {
                    old->c_last_hf =  old->c_first_hf = NULL;
                } else {
                    hp_prev->next = NULL;
                    old->c_last_hf =  hp_prev;
                }
            } else {
                if (hp == old->c_first_hf) {
                    old->c_first_hf = next;
                } else {
                    hp_prev->next = next;
                }
            }

            /* Put node hp in the new CT. */
            if (new->c_first_hf == NULL) {
                new->c_first_hf = hp;
            } else {
                new->c_last_hf->next = hp;
            }
            new->c_last_hf = hp;
        } else {
            /* A Content- header, leave in old. */
            hp_prev = hp;
        }

        hp = next;
    }
}


/*
 * Set content type.
 */
static int
set_ct_type (CT ct, int type, int subtype, int encoding, const char *charset)
{
    char *typename = ct_type_str (type);
    char *subtypename = ct_subtype_str (type, subtype);
    /* E.g, " text/plain" */
    char *type_subtypename = concat (" ", typename, "/", subtypename, NULL);
    /* E.g, " text/plain\n" */
    char *name_plus_nl = concat (type_subtypename, "\n", NULL);
    bool found_content_type = false;
    HF hf;
    char *old_charset = NULL;
    char *semicolon_on = strchr (ct->c_ctline, ';');
    char *addl = mh_xstrdup(FENDNULL (semicolon_on));
    const char *cp = NULL;
    char *ctline;
    int status;

    /* If charset is provided, find the old charset, if any. */
    if (charset) {
        for (hf = ct->c_first_hf; hf; hf = hf->next) {
            if (! strcasecmp (hf->name, TYPE_FIELD)) {
                const char *charset_begin = strcasestr (hf->value, "charset=");
                if (charset_begin) {
                    old_charset = concat (charset_begin + 8, NULL);
                    for (char *c = old_charset; *c; ++c) {
                        if (isspace ((unsigned char) *c)) {
                            *c = '\0';
                            break;
                        }
                    }
                }
            }
            break;
        }

        if (addl) {
            char *old = addl;

            if (strcasestr (addl, "charset=") && old_charset) {
                addl = mh_xstrdup (addl);
                replace_substring(&addl, old_charset, charset);
            } else {
                /* no charset parameter, so add to existing parameters */
                addl = addl
                    ?  concat (addl, "; charset=", charset, NULL)
                    :  concat ("; charset=", charset, NULL);
            }
            free (old);
        }

        free (old_charset);
    }

    /* Update/add Content-Type header field. */
    for (hf = ct->c_first_hf; hf; hf = hf->next) {
        if (! strcasecmp (TYPE_FIELD, hf->name)) {
            found_content_type = true;
            free (hf->value);
            hf->value = addl
                ?  concat (type_subtypename, addl, "\n", NULL)
                :  mh_xstrdup (name_plus_nl);
        }
    }
    if (! found_content_type) {
        add_header (ct, mh_xstrdup (TYPE_FIELD),
                    (cp = strchr (ct->c_ctline, ';'))
                    ?  concat (type_subtypename, cp, "\n", NULL)
                    :  mh_xstrdup (name_plus_nl));
    }

    /* Some of these might not be used, but set them anyway. */
    ctline = addl
        ?  concat (type_subtypename, addl, NULL)
        :  concat (type_subtypename, NULL);
    free (addl);
    free (ct->c_ctline);
    ct->c_ctline = ctline;
    /* Leave other ctinfo members as they were. */
    free (ct->c_ctinfo.ci_type);
    ct->c_ctinfo.ci_type = mh_xstrdup (typename);
    free (ct->c_ctinfo.ci_subtype);
    ct->c_ctinfo.ci_subtype = mh_xstrdup (subtypename);
    ct->c_type = type;
    ct->c_subtype = subtype;

    free (name_plus_nl);
    free (type_subtypename);

    status = set_ce (ct, encoding);

    return status;
}


/*
 * It's not necessary to update the charset parameter of a Content-Type
 * header for a text part.  According to RFC 2045 Sec. 6.4, the body
 * (content) was originally in the specified charset, "and will be in
 * that character set again after decoding."
 */
static int
decode_text_parts (CT ct, int encoding, const char *decodetypes,
                   int *message_mods)
{
    int status = OK;
    int lf_line_endings = 0;

    switch (ct->c_type) {
    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) ct->c_ctparams;
        struct part *part;

        /* Should check to see if the body for this part is encoded?
           For now, it gets passed along as-is by InitMultiPart(). */
        for (part = m->mp_parts; status == OK  &&  part; part = part->mp_next) {
            status = decode_text_parts (part->mp_part, encoding, decodetypes,
                                        message_mods);
        }
        break;
    }

    case CT_MESSAGE:
        if (ct->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) ct->c_ctparams;

            status = decode_text_parts (e->eb_content, encoding, decodetypes,
                                        message_mods);
        }
        break;

    default:
        if (! should_decode(decodetypes, ct->c_ctinfo.ci_type, ct->c_ctinfo.ci_subtype)) {
            break;
        }

        lf_line_endings =
            ct->c_ctparams  &&  ((struct text *) ct->c_ctparams)->lf_line_endings;

        switch (ct->c_encoding) {
        case CE_BASE64:
        case CE_QUOTED: {
            int ct_encoding;

            if (decode_part (ct) == OK  &&  ct->c_cefile.ce_file) {
                const char *reason = NULL;

                if ((ct_encoding = content_encoding (ct, &reason)) == CE_BINARY
                    &&  encoding != CE_BINARY) {
                    /* The decoding isn't acceptable so discard it.
                       Leave status as OK to allow other transformations. */
                    if (verbosw) {
                        report (NULL, ct->c_partno, ct->c_file,
                                "will not decode%s because it is binary (%s)",
                                ct->c_partno  ?  ""
                                              :  (FENDNULL(ct->c_ctline)),
                                reason);
                    }
                    (void) m_unlink (ct->c_cefile.ce_file);
                    free (ct->c_cefile.ce_file);
                    ct->c_cefile.ce_file = NULL;
                } else if (ct->c_encoding == CE_QUOTED  &&
                           ct_encoding == CE_8BIT  &&  encoding == CE_7BIT) {
                    /* The decoding isn't acceptable so discard it.
                       Leave status as OK to allow other transformations. */
                    if (verbosw) {
                        report (NULL, ct->c_partno, ct->c_file,
                                "will not decode%s because it is 8bit",
                                ct->c_partno  ?  ""
                                              :  (FENDNULL(ct->c_ctline)));
                    }
                    (void) m_unlink (ct->c_cefile.ce_file);
                    free (ct->c_cefile.ce_file);
                    ct->c_cefile.ce_file = NULL;
                } else {
                    int enc;

                    if (ct_encoding == CE_BINARY) {
                        enc = CE_BINARY;
                    } else if (ct_encoding == CE_8BIT  &&  encoding == CE_7BIT) {
                        enc = CE_QUOTED;
                    } else {
                        enc = ct_encoding;
                    }
                    if (set_ce (ct, enc) == OK) {
                        ++*message_mods;
                        if (verbosw) {
                            report (NULL, ct->c_partno, ct->c_file, "decode%s",
                                    FENDNULL(ct->c_ctline));
                        }
                        if (lf_line_endings) {
                            strip_crs (ct, message_mods);
                        }
                    } else {
                        status = NOTOK;
                    }
                }
            } else {
                status = NOTOK;
            }
            break;
        }
        case CE_8BIT:
        case CE_7BIT:
            if (lf_line_endings) {
                strip_crs (ct, message_mods);
            }
            break;
        default:
            break;
        }

        break;
    }

    return status;
}


/*
 * Determine if the part with type[/subtype] should be decoded, according to
 * decodetypes (which came from the -decodetypes switch).
 */
static int
should_decode(const char *decodetypes, const char *type, const char *subtype)
{
    /* Quick search for matching type[/subtype] in decodetypes:  bracket
       decodetypes with commas, then search for ,type, and ,type/subtype, in
       it. */

    bool found_match = false;
    char *delimited_decodetypes = concat(",", decodetypes, ",", NULL);
    char *delimited_type = concat(",", type, ",", NULL);

    if (nmh_strcasestr(delimited_decodetypes, delimited_type)) {
        found_match = true;
    } else if (subtype != NULL) {
        char *delimited_type_subtype =
            concat(",", type, "/", subtype, ",", NULL);

        if (nmh_strcasestr(delimited_decodetypes, delimited_type_subtype)) {
            found_match = true;
        }
        free(delimited_type_subtype);
    }

    free(delimited_type);
    free(delimited_decodetypes);

    return found_match;
}


/*
 * See if the decoded content is 7bit, 8bit, or binary.  It's binary
 * if it has any NUL characters, a CR not followed by a LF, or lines
 * greater than 998 characters in length.  If binary, reason is set
 *  to a string explaining why.
 */
static int
content_encoding (CT ct, const char **reason)
{
    CE ce = &ct->c_cefile;
    int encoding = CE_7BIT;

    if (ce->ce_file) {
        size_t line_len = 0;
        char buffer[NMH_BUFSIZ];
        size_t inbytes;

        if (! ce->ce_fp  &&  (ce->ce_fp = fopen (ce->ce_file, "r")) == NULL) {
            advise (ce->ce_file, "unable to open for reading");
            return CE_UNKNOWN;
        }

        fseeko (ce->ce_fp, 0L, SEEK_SET);
        while (encoding != CE_BINARY  &&
               (inbytes = fread (buffer, 1, sizeof buffer, ce->ce_fp)) > 0) {
            char *cp;
            size_t i;
            int last_char_was_cr = 0;

            for (i = 0, cp = buffer; i < inbytes; ++i, ++cp) {
                if (*cp == '\0'  ||  ++line_len > 998  ||
                    (*cp != '\n'  &&  last_char_was_cr)) {
                    encoding = CE_BINARY;
                    if (*cp == '\0') {
                        *reason = "null character";
                    } else if (line_len > 998) {
                        *reason = "line length > 998";
                    } else if (*cp != '\n'  &&  last_char_was_cr) {
                        *reason = "CR not followed by LF";
                    } else {
                        /* Should not reach this. */
                        *reason = "";
                    }
                    break;
                }
                if (*cp == '\n') {
                    line_len = 0;
                } else if (! isascii ((unsigned char) *cp)) {
                    encoding = CE_8BIT;
                }

                last_char_was_cr = *cp == '\r';
            }
        }

        fclose (ce->ce_fp);
        ce->ce_fp = NULL;
    } /* else should never happen */

    return encoding;
}


/*
 * Strip carriage returns from content.
 */
static int
strip_crs (CT ct, int *message_mods)
{
    char *charset = content_charset (ct);
    int status = OK;

    /* Only strip carriage returns if content is ASCII or another
       charset that has the same readily recognizable CR followed by a
       LF.  We can include UTF-8 here because if the high-order bit of
       a UTF-8 byte is 0, then it must be a single-byte ASCII
       character. */
    if (! strcasecmp (charset, "US-ASCII")  ||
        ! strcasecmp (charset, "UTF-8")  ||
        ! strncasecmp (charset, "ISO-8859-", 9)  ||
        ! strncasecmp (charset, "WINDOWS-12", 10)) {
        char **file = NULL;
        FILE **fp = NULL;
        size_t begin;
        size_t end;
        bool has_crs = false;
        bool opened_input_file = false;

        if (ct->c_cefile.ce_file) {
            file = &ct->c_cefile.ce_file;
            fp = &ct->c_cefile.ce_fp;
            begin = end = 0;
        } else if (ct->c_file) {
            file = &ct->c_file;
            fp = &ct->c_fp;
            begin = (size_t) ct->c_begin;
            end = (size_t) ct->c_end;
        } /* else don't know where the content is */

        if (file  &&  *file  &&  fp) {
            if (! *fp) {
                if ((*fp = fopen (*file, "r")) == NULL) {
                    advise (*file, "unable to open for reading");
                    status = NOTOK;
                } else {
                    opened_input_file = true;
                }
            }
        }

        if (fp  &&  *fp) {
            char buffer[NMH_BUFSIZ];
            size_t bytes_read;
            size_t bytes_to_read =
                end > 0 && end > begin  ?  end - begin  :  sizeof buffer;

            fseeko (*fp, begin, SEEK_SET);
            while ((bytes_read = fread (buffer, 1,
                                        min (bytes_to_read, sizeof buffer),
                                        *fp)) > 0) {
                /* Look for CR followed by a LF.  This is supposed to
                   be text so there should be LF's.  If not, don't
                   modify the content. */
                char *cp;
                size_t i;
                bool last_char_was_cr = false;

                if (end > 0) { bytes_to_read -= bytes_read; }

                for (i = 0, cp = buffer; i < bytes_read; ++i, ++cp) {
                    if (*cp == '\n'  &&  last_char_was_cr) {
                        has_crs = true;
                        break;
                    }

                    last_char_was_cr = *cp == '\r';
                }
            }

            if (has_crs) {
                int fd;
                char *stripped_content_file;
                char *tempfile = m_mktemp2 (NULL, invo_name, &fd, NULL);

                if (tempfile == NULL) {
                    die("unable to create temporary file in %s",
                           get_temp_dir());
                }
                stripped_content_file = mh_xstrdup (tempfile);

                /* Strip each CR before a LF from the content. */
                fseeko (*fp, begin, SEEK_SET);
                while ((bytes_read = fread (buffer, 1, sizeof buffer, *fp)) >
                       0) {
                    char *cp;
                    size_t i;
                    bool last_char_was_cr = false;

                    for (i = 0, cp = buffer; i < bytes_read; ++i, ++cp) {
                        if (*cp == '\r') {
                            last_char_was_cr = true;
                        } else if (last_char_was_cr) {
                            if (*cp != '\n') {
                                if (write (fd, "\r", 1) < 0) {
                                    advise (tempfile, "CR write");
                                }
                            }
                            if (write (fd, cp, 1) < 0) {
                                advise (tempfile, "write");
                            }
                            last_char_was_cr = false;
                        } else {
                            if (write (fd, cp, 1) < 0) {
                                advise (tempfile, "write");
                            }
                            last_char_was_cr = false;
                        }
                    }
                }

                if (close (fd)) {
                    inform("unable to write temporary file %s, continuing...",
                              stripped_content_file);
                    (void) m_unlink (stripped_content_file);
                    free(stripped_content_file);
                    status = NOTOK;
                } else {
                    /* Replace the decoded file with the converted one. */
                    if (ct->c_cefile.ce_file && ct->c_cefile.ce_unlink)
                        (void) m_unlink (ct->c_cefile.ce_file);

                    free(ct->c_cefile.ce_file);
                    ct->c_cefile.ce_file = stripped_content_file;
                    ct->c_cefile.ce_unlink = 1;

                    ++*message_mods;
                    if (verbosw) {
                        report (NULL, ct->c_partno,
                                begin == 0 && end == 0  ?  ""  :  *file,
                                "stripped CRs");
                    }
                }
            }

            if (opened_input_file) {
                fclose (*fp);
                *fp = NULL;
            }
        }
    }

    free (charset);

    return status;
}


/*
 * Add/update, if necessary, the message C-T-E, based on the least restrictive
 * of the part C-T-E's.
 */
static void
update_cte (CT ct)
{
    const int least_restrictive_enc = least_restrictive_encoding (ct);

    if (least_restrictive_enc != CE_UNKNOWN  &&
        least_restrictive_enc != CE_7BIT) {
        char *cte = concat (" ", ce_str (least_restrictive_enc), "\n", NULL);
        HF hf;
        bool found_cte = false;

        /* Update/add Content-Transfer-Encoding header field. */
        for (hf = ct->c_first_hf; hf; hf = hf->next) {
            if (! strcasecmp (ENCODING_FIELD, hf->name)) {
                found_cte = true;
                free (hf->value);
                hf->value = cte;
            }
        }
        if (! found_cte) {
            add_header (ct, mh_xstrdup (ENCODING_FIELD), cte);
        }
    }
}


/*
 * Find the least restrictive encoding (7bit, 8bit, binary) of the parts
 * within a message.
 */
static int
least_restrictive_encoding (CT ct)
{
    int encoding = CE_UNKNOWN;

    switch (ct->c_type) {
    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) ct->c_ctparams;
        struct part *part;

        for (part = m->mp_parts; part; part = part->mp_next) {
            const int part_encoding =
                least_restrictive_encoding (part->mp_part);

            if (less_restrictive (encoding, part_encoding)) {
                encoding = part_encoding;
            }
        }
        break;
    }

    case CT_MESSAGE:
        if (ct->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) ct->c_ctparams;
            const int part_encoding =
                least_restrictive_encoding (e->eb_content);

            if (less_restrictive (encoding, part_encoding)) {
                encoding = part_encoding;
            }
        }
        break;

    default: {
        if (less_restrictive (encoding, ct->c_encoding)) {
            encoding = ct->c_encoding;
        }
    }}

    return encoding;
}


/*
 * Return whether the second encoding is less restrictive than the first, where
 * "less restrictive" is in the sense used by RFC 2045 Secs. 6.1 and 6.4.  So,
 *   CE_BINARY is less restrictive than CE_8BIT and
 *   CE_8BIT is less restrictive than CE_7BIT.
 */
static int
less_restrictive (int encoding, int second_encoding)
{
    switch (second_encoding) {
    case CE_BINARY:
        return encoding != CE_BINARY;
    case CE_8BIT:
        return encoding != CE_BINARY  &&  encoding != CE_8BIT;
    case CE_7BIT:
        return encoding != CE_BINARY  &&  encoding != CE_8BIT  &&
            encoding != CE_7BIT;
    default :
        return 0;
    }
}


/*
 * Convert character set of each part.
 */
static int
convert_charsets (CT ct, char *dest_charset, int *message_mods)
{
    int status = OK;

    switch (ct->c_type) {
    case CT_TEXT:
        if (ct->c_subtype == TEXT_PLAIN) {
            char *const ct_charset = content_charset (ct);

            if (strcasecmp (ct_charset, dest_charset)) {
                status = convert_charset (ct, dest_charset, message_mods);
                if (status == OK) {
                    if (verbosw) {
                        report (NULL, ct->c_partno, ct->c_file,
                                "convert %s to %s", ct_charset, dest_charset);
                    }
                } else {
                    report ("iconv", ct->c_partno, ct->c_file,
                            "failed to convert %s to %s", ct_charset, dest_charset);
                }
            }
            free (ct_charset);
        }
        break;

    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) ct->c_ctparams;
        struct part *part;

        /* Should check to see if the body for this part is encoded?
           For now, it gets passed along as-is by InitMultiPart(). */
        for (part = m->mp_parts; status == OK  &&  part; part = part->mp_next) {
            status =
                convert_charsets (part->mp_part, dest_charset, message_mods);
        }
        break;
    }

    case CT_MESSAGE:
        if (ct->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) ct->c_ctparams;

            status =
                convert_charsets (e->eb_content, dest_charset, message_mods);
        }
        break;

    default:
        break;
    }

    return status;
}


/*
 * Fix various problems that aren't handled elsewhere.  These
 * are fixed unconditionally:  there are no switches to disable
 * them.  Currently, "problems" are these:
 * 1) remove extraneous semicolon at the end of a header parameter list
 * 2) replace RFC 2047 encoding with RFC 2231 encoding of name and
 *    filename parameters in Content-Type and Content-Disposition
 *    headers, respectively.
 */
static int
fix_always (CT *ctp, const fix_transformations *fx, int *message_mods)
{
    int status = OK;

    switch ((*ctp)->c_type) {
    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) (*ctp)->c_ctparams;
        struct part *part;

        for (part = m->mp_parts; status == OK  &&  part; part = part->mp_next) {
            status = fix_always (&part->mp_part, fx, message_mods);
        }
        break;
    }

    case CT_MESSAGE:
        if ((*ctp)->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) (*ctp)->c_ctparams;

            status = fix_always (&e->eb_content, fx, message_mods);
        }
        break;

    default: {
        HF hf;

        if ((*ctp)->c_first_hf) {
            fix_filename_encoding (*ctp);
        }

        for (hf = (*ctp)->c_first_hf; hf; hf = hf->next) {
            size_t len = strlen (hf->value);

            if (strcasecmp (hf->name, TYPE_FIELD) != 0  &&
                strcasecmp (hf->name, DISPO_FIELD) != 0) {
                /* Only do this for Content-Type and
                   Content-Disposition fields because those are the
                   only headers that parse_mime() warns about. */
                continue;
            }

            /* whitespace following a trailing ';' will be nuked as well */
            if (hf->value[len - 1] == '\n') {
                while (isspace((unsigned char)(hf->value[len - 2]))) {
                    if (len-- == 0) { break; }
                }
            }

            if (hf->value[len - 2] == ';') {
                /* Remove trailing ';' from parameter value. */
                hf->value[len - 2] = '\n';
                hf->value[len - 1] = '\0';

                /* Also, if Content-Type parameter, remove trailing ';'
                   from (*ctp)->c_ctline.  This probably isn't necessary
                   but can't hurt. */
                if (strcasecmp(hf->name, TYPE_FIELD) == 0 && (*ctp)->c_ctline) {
                    size_t l = strlen((*ctp)->c_ctline) - 1;
                    while (isspace((unsigned char)((*ctp)->c_ctline[l])) ||
                           (*ctp)->c_ctline[l] == ';') {
                        (*ctp)->c_ctline[l--] = '\0';
                        if (l == 0) { break; }
                    }
                }

                ++*message_mods;
                if (verbosw) {
                    report (NULL, (*ctp)->c_partno, (*ctp)->c_file,
                            "remove trailing ; from %s parameter value",
                            hf->name);
                }
            }
        }

        if (fx->checkbase64  &&  (*ctp)->c_encoding == CE_BASE64) {
            status = check_base64_encoding (ctp);
        }
    }}

    return status;
}


/*
 * Decodes UTF-8 encoded header values.  Similar to fix_filename_param(), but
 * does not modify any MIME parameter values.
 */
static int
decode_header_field_bodies (CT ct, const char *dest_charset, int *message_mods)
{
    int status = OK;

    switch (ct->c_type) {
    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) ct->c_ctparams;
        struct part *part;

        for (part = m->mp_parts; status == OK  &&  part; part = part->mp_next) {
            status = decode_header_field_bodies (part->mp_part, dest_charset,
                                                 message_mods);
        }
        break;
    }

    case CT_MESSAGE:
        if (ct->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) ct->c_ctparams;

            status = decode_header_field_bodies (e->eb_content, dest_charset,
                                                 message_mods);
        }
        break;
    }

    HF hf;

    for (hf = ct->c_first_hf; hf; hf = hf->next) {
        status = decode_field_body(hf->name, &hf->value, dest_charset,
                                   message_mods);
    }

    return status;
}


static int
decode_field_body (const char *name, char **value, const char *dest_charset,
                   int *message_mods)
{
    /*
       Decode the header field body as follows.  We don't want to produce a
       decoded string with embedded NULs because that can interfere with
       parsing of the message header.
       1. Attempt to decode body, given any charset for the encoding.
       2. If unable to decode or if any NUL octets in the decoded text, leave
          the body encoded.  If unable to decode, that's allowed by
          RFC 2047 § 6.2.  If any NULs, that seems to be in the same spirit.
    */
    ssize_t len = NMH_BUFSIZ;
    char *buffer = mh_xmalloc (len);
    int status = OK;

    if (*value  &&  strstr (*value, "?=")) {
        /* Looks like an RFC 2047 encoded parameter. */

        if ((len = decode_rfc2047 (*value, buffer, len, dest_charset)) > 0) {
            /* decode_rfc2047() could truncate if the buffer fills up.
               Detect and discard if that happened.  Also discard if
               there are any embedded NULs. */
            if (len < NMH_BUFSIZ - 1  &&  ! contains_nuls (buffer, len)  &&
                strcmp (*value, buffer)) {
                char *cp;
                /* Successfully decoded *value. */
                unfold_header (&buffer, len);
                len = strlen (buffer);
                /* Restore the trailing newline that unfold_header() removed. */
                cp = &buffer[len];
                *cp++ = '\n';
                *cp = '\0';
                *value = mh_xrealloc (*value, len + 2);
                strncpy (*value, buffer, len + 2);
                ++message_mods;
            }
        } else {
            char *val = cpytrim (*value);
            inform ("failed to decode %s value %s", name, val);
            free (val);
            status = NOTOK;
        }
    }

    free (buffer);
    return status;
}


/*
 * Returns whether a string of the specific charset has any
 * embedded NUL octects.
 */
static bool
contains_nuls(const char *string, ssize_t len)
{
    for (const char *cp = string; len > 1; ++cp, --len) {
        if (*cp == '\0') {
            return true;
        }
    }

    return false;
}


/*
 * Factor out common code for loops in fix_filename_encoding().
 */
static int
fix_filename_param (char *name, char *value, PM *first_pm, PM *last_pm)
{
    bool fixed = false;

    if (has_prefix(value, "=?") && has_suffix(value, "?=")) {
        /* Looks like an RFC 2047 encoded parameter. */
        char decoded[PATH_MAX + 1];

        if (decode_rfc2047 (value, decoded, sizeof decoded, NULL) > 0) {
            /* Encode using RFC 2231. */
            replace_param (first_pm, last_pm, name, decoded, 0);
            fixed = true;
        } else {
            inform("failed to decode %s parameter %s", name, value);
        }
    }

    return fixed;
}


/*
 * Replace RFC 2047 encoding with RFC 2231 encoding of name and
 * filename parameters in Content-Type and Content-Disposition
 * headers, respectively.
 */
static int
fix_filename_encoding (CT ct)
{
    PM pm;
    HF hf;
    int fixed = 0;

    for (pm = ct->c_ctinfo.ci_first_pm; pm; pm = pm->pm_next) {
        if (pm->pm_name  &&  pm->pm_value  &&
            strcasecmp (pm->pm_name, "name") == 0) {
            fixed = fix_filename_param (pm->pm_name, pm->pm_value,
                                        &ct->c_ctinfo.ci_first_pm,
                                        &ct->c_ctinfo.ci_last_pm);
        }
    }

    for (pm = ct->c_dispo_first; pm; pm = pm->pm_next) {
        if (pm->pm_name  &&  pm->pm_value  &&
            strcasecmp (pm->pm_name, "filename") == 0) {
            fixed = fix_filename_param (pm->pm_name, pm->pm_value,
                                        &ct->c_dispo_first,
                                        &ct->c_dispo_last);
        }
    }

    /* Fix hf values to correspond. */
    for (hf = ct->c_first_hf; fixed && hf; hf = hf->next) {
        enum { OTHER, TYPE_HEADER, DISPO_HEADER } field = OTHER;

        if (strcasecmp (hf->name, TYPE_FIELD) == 0) {
            field = TYPE_HEADER;
        } else if (strcasecmp (hf->name, DISPO_FIELD) == 0) {
            field = DISPO_HEADER;
        }

        if (field != OTHER) {
            const char *const semicolon_loc = strchr (hf->value, ';');

            if (semicolon_loc) {
                const size_t len =
                    strlen (hf->name) + 1 + semicolon_loc - hf->value;
                const char *const params =
                    output_params (len,
                                   field == TYPE_HEADER
                                   ? ct->c_ctinfo.ci_first_pm
                                   : ct->c_dispo_first,
                                   NULL, 0);
                const char *const new_params = concat (params, "\n", NULL);

                replace_substring (&hf->value, semicolon_loc, new_params);
                free((void *)new_params); /* Cast away const.  Sigh. */
                free((void *)params);
            }
        }
    }

    return OK;
}


/*
 * Output content in input file to output file.
 */
static int
write_content (CT ct, const char *input_filename, char *outfile, FILE *outfp,
               int modify_inplace, int message_mods)
{
    int status = OK;

    if (modify_inplace) {
        if (message_mods > 0) {
            if ((status = output_message_fp (ct, outfp, outfile)) == OK) {
                char *infile = input_filename
                    ?  mh_xstrdup (input_filename)
                    :  mh_xstrdup (ct->c_file ? ct->c_file : "-");

                if (remove_file (infile) == OK) {
                    if (rename (outfile, infile)) {
                        /* Rename didn't work, possibly because of an
                           attempt to rename across filesystems.  Try
                           brute force copy. */
                        int old = open (outfile, O_RDONLY);
                        int new =
                            open (infile, O_WRONLY | O_CREAT, m_gmprot ());
                        int i = -1;

                        if (old != -1  &&  new != -1) {
                            char buffer[NMH_BUFSIZ];

                            while ((i = read (old, buffer, sizeof buffer)) >
                                   0) {
                                if (write (new, buffer, i) != i) {
                                    i = -1;
                                    break;
                                }
                            }
                        }
                        if (new != -1) { close (new); }
                        if (old != -1) { close (old); }
                        (void) m_unlink (outfile);

                        if (i < 0) {
                            /* The -file argument processing used path() to
                               expand filename to absolute path. */
                            int file = ct->c_file  &&  ct->c_file[0] == '/';

                            inform("unable to rename %s %s to %s, continuing...",
                                      file ? "file" : "message", outfile,
                                      infile);
                            status = NOTOK;
                        }
                    }
                } else {
                    inform("unable to remove input file %s, "
                        "not modifying it, continuing...", infile);
                    (void) m_unlink (outfile);
                    status = NOTOK;
                }

                free (infile);
            } else {
                status = NOTOK;
            }
        } else {
            /* No modifications and didn't need the tmp outfile. */
            (void) m_unlink (outfile);
        }
    } else {
        /* Output is going to some file.  Produce it whether or not
           there were modifications. */
        status = output_message_fp (ct, outfp, outfile);
    }

    flush_errors ();
    return status;
}


/*
 * parse_mime() does not set lf_line_endings in struct text, so use this
 * function to do it.  It touches the parts the decodetypes identifies.
 */
static void
set_text_ctparams(CT ct, char *decodetypes, int lf_line_endings)
{
    switch (ct->c_type) {
    case CT_MULTIPART: {
        struct multipart *m = (struct multipart *) ct->c_ctparams;
        struct part *part;

        for (part = m->mp_parts; part; part = part->mp_next) {
            set_text_ctparams(part->mp_part, decodetypes, lf_line_endings);
        }
        break;
    }

    case CT_MESSAGE:
        if (ct->c_subtype == MESSAGE_EXTERNAL) {
            struct exbody *e = (struct exbody *) ct->c_ctparams;

            set_text_ctparams(e->eb_content, decodetypes, lf_line_endings);
        }
        break;

    default:
        if (should_decode(decodetypes, ct->c_ctinfo.ci_type, ct->c_ctinfo.ci_subtype)) {
            if (ct->c_ctparams == NULL) {
                ct->c_ctparams = mh_xcalloc(1, sizeof (struct text));
            }
            ((struct text *) ct->c_ctparams)->lf_line_endings = lf_line_endings;
        }
    }
}


/*
 * If "rmmproc" is defined, call that to remove the file.  Otherwise,
 * use the standard MH backup file.
 */
static int
remove_file (const char *file)
{
    if (rmmproc) {
        char *rmm_command = concat (rmmproc, " ", file, NULL);
        int status = system (rmm_command);

        free (rmm_command);
        return WIFEXITED (status)  ?  WEXITSTATUS (status)  :  NOTOK;
    }
    /* This is OK for a non-message file, it still uses the
       BACKUP_PREFIX form.  The backup file will be in the same
       directory as file. */
    return rename (file, m_backup (file));
}


/*
 * Output formatted message to user.
 */
static void
report (char *what, char *partno, char *filename, char *message, ...)
{
    va_list args;
    char *fmt;

    if (verbosw) {
        va_start (args, message);
        fmt = concat (filename, partno ? " part " : ", ",
                      FENDNULL(partno), partno ? ", " : "", message, NULL);

        advertise (what, NULL, fmt, args);

        free (fmt);
        va_end (args);
    }
}


static void
pipeser (int i)
{
    if (i == SIGQUIT) {
        fflush (stdout);
        fprintf (stderr, "\n");
        fflush (stderr);
    }

    done (1);
    /* NOTREACHED */
}