[apps/madmutt.git] / sendlib.c

/*
 * Copyright notice from original mutt:
 * Copyright (C) 1996-2002 Michael R. Elkins <me@mutt.org>
 *
 * This file is part of mutt-ng, see http://www.muttng.org/.
 * It's licensed under the GNU General Public License,
 * please see the file GPL in the top level source directory.
 */

#define _SENDLIB_C 1

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <lib-lib/mem.h>
#include <lib-lib/ascii.h>
#include <lib-lib/str.h>
#include <lib-lib/macros.h>
#include <lib-lib/file.h>

#include <lib-mime/mime.h>

#include <lib-ui/curses.h>

#include "mutt.h"
#include "handler.h"
#include "recvattach.h"
#include "mx.h"
#include "copy.h"
#include "pager.h"
#include "charset.h"
#include <lib-crypt/crypt.h>
#include "mutt_idna.h"

#include "lib/debug.h"

#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <sys/stat.h>
#include <signal.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <sys/utsname.h>

#ifdef USE_LIBESMTP
# include "mutt_libesmtp.h"
#endif /* USE_LIBESMTP */

#ifdef USE_NNTP
#include <nntp.h>
#endif

#ifdef HAVE_SYSEXITS_H
#include <sysexits.h>
#else /* Make sure EX_OK is defined <philiph@pobox.com> */
#define EX_OK 0
#endif

/* If you are debugging this file, comment out the following line. */
/*#define NDEBUG*/

#ifdef NDEBUG
#define assert(x)
#else
#include <assert.h>
#endif

#define DISPOSITION(X) X==DISPATTACH?"attachment":"inline"

static char MsgIdPfx = 'A';

static void transform_to_7bit (BODY * a, FILE * fpin);

static void encode_quoted (FGETCONV * fc, FILE * fout, int istext)
{
  int c, linelen = 0;
  char line[77], savechar;

  while ((c = fgetconv (fc)) != EOF) {
    /* Wrap the line if needed. */
    if (linelen == 76 && ((istext && c != '\n') || !istext)) {
      /* If the last character is "quoted", then be sure to move all three
       * characters to the next line.  Otherwise, just move the last
       * character...
       */
      if (line[linelen - 3] == '=') {
        line[linelen - 3] = 0;
        fputs (line, fout);
        fputs ("=\n", fout);
        line[linelen] = 0;
        line[0] = '=';
        line[1] = line[linelen - 2];
        line[2] = line[linelen - 1];
        linelen = 3;
      }
      else {
        savechar = line[linelen - 1];
        line[linelen - 1] = '=';
        line[linelen] = 0;
        fputs (line, fout);
        fputc ('\n', fout);
        line[0] = savechar;
        linelen = 1;
      }
    }

    /* Escape lines that begin with/only contain "the message separator". */
    if (linelen == 4 && !m_strncmp("From", line, 4)) {
      m_strcpy(line, sizeof(line), "=46rom");
      linelen = 6;
    }
    else if (linelen == 4 && !m_strncmp("from", line, 4)) {
      m_strcpy(line, sizeof(line), "=66rom");
      linelen = 6;
    }
    else if (linelen == 1 && line[0] == '.') {
      m_strcpy(line, sizeof(line), "=2E");
      linelen = 3;
    }


    if (c == '\n' && istext) {
      /* Check to make sure there is no trailing space on this line. */
      if (linelen > 0
          && (line[linelen - 1] == ' ' || line[linelen - 1] == '\t')) {
        if (linelen < 74) {
          sprintf (line + linelen - 1, "=%2.2X",
                   (unsigned char) line[linelen - 1]);
          fputs (line, fout);
        }
        else {
          int savechar = line[linelen - 1];

          line[linelen - 1] = '=';
          line[linelen] = 0;
          fputs (line, fout);
          fprintf (fout, "\n=%2.2X", (unsigned char) savechar);
        }
      }
      else {
        line[linelen] = 0;
        fputs (line, fout);
      }
      fputc ('\n', fout);
      linelen = 0;
    }
    else if (c != 9 && (c < 32 || c > 126 || c == '=')) {
      /* Check to make sure there is enough room for the quoted character.
       * If not, wrap to the next line.
       */
      if (linelen > 73) {
        line[linelen++] = '=';
        line[linelen] = 0;
        fputs (line, fout);
        fputc ('\n', fout);
        linelen = 0;
      }
      sprintf (line + linelen, "=%2.2X", (unsigned char) c);
      linelen += 3;
    }
    else {
      /* Don't worry about wrapping the line here.  That will happen during
       * the next iteration when I'll also know what the next character is.
       */
      line[linelen++] = c;
    }
  }

  /* Take care of anything left in the buffer */
  if (linelen > 0) {
    if (line[linelen - 1] == ' ' || line[linelen - 1] == '\t') {
      /* take care of trailing whitespace */
      if (linelen < 74)
        sprintf (line + linelen - 1, "=%2.2X",
                 (unsigned char) line[linelen - 1]);
      else {
        savechar = line[linelen - 1];
        line[linelen - 1] = '=';
        line[linelen] = 0;
        fputs (line, fout);
        fputc ('\n', fout);
        sprintf (line, "=%2.2X", (unsigned char) savechar);
      }
    }
    else
      line[linelen] = 0;
    fputs (line, fout);
  }
}

static char b64_buffer[3];
static short b64_num;
static short b64_linelen;

static void b64_flush (FILE * fout)
{
  short i;

  if (!b64_num)
    return;

  if (b64_linelen >= 72) {
    fputc ('\n', fout);
    b64_linelen = 0;
  }

  for (i = b64_num; i < 3; i++)
    b64_buffer[i] = '\0';

  fputc(__m_b64chars[(b64_buffer[0] >> 2) & 0x3f], fout);
  b64_linelen++;
  fputc(__m_b64chars
         [((b64_buffer[0] & 0x3) << 4) | ((b64_buffer[1] >> 4) & 0xf)], fout);
  b64_linelen++;

  if (b64_num > 1) {
    fputc (__m_b64chars
           [((b64_buffer[1] & 0xf) << 2) | ((b64_buffer[2] >> 6) & 0x3)],
           fout);
    b64_linelen++;
    if (b64_num > 2) {
      fputc (__m_b64chars[b64_buffer[2] & 0x3f], fout);
      b64_linelen++;
    }
  }

  while (b64_linelen % 4) {
    fputc ('=', fout);
    b64_linelen++;
  }

  b64_num = 0;
}


static void b64_putc (char c, FILE * fout)
{
  if (b64_num == 3)
    b64_flush (fout);

  b64_buffer[b64_num++] = c;
}


static void encode_base64 (FGETCONV * fc, FILE * fout, int istext)
{
  int ch, ch1 = EOF;

  b64_num = b64_linelen = 0;

  while ((ch = fgetconv (fc)) != EOF) {
    if (istext && ch == '\n' && ch1 != '\r')
      b64_putc ('\r', fout);
    b64_putc (ch, fout);
    ch1 = ch;
  }
  b64_flush (fout);
  fputc ('\n', fout);
}

static void encode_8bit (FGETCONV * fc, FILE * fout, int istext)
{
  int ch;

  while ((ch = fgetconv (fc)) != EOF)
    fputc (ch, fout);
}


int mutt_write_mime_header (BODY * a, FILE * f)
{
  PARAMETER *p;
  char buffer[STRING];
  char *t;
  char *fn;
  int len;
  int tmplen;
  int encode;

  fprintf (f, "Content-Type: %s/%s", TYPE (a), a->subtype);

  if (a->parameter) {
    len = 25 + m_strlen(a->subtype);        /* approximate len. of content-type */

    for (p = a->parameter; p; p = p->next) {
      char *tmp;

      if (!p->value)
        continue;

      fputc (';', f);

      buffer[0] = 0;
      tmp = m_strdup(p->value);
      encode = rfc2231_encode_string (&tmp);
      rfc822_strcpy(buffer, sizeof(buffer), tmp, MimeSpecials);

      /* Dirty hack to make messages readable by Outlook Express 
       * for the Mac: force quotes around the boundary parameter
       * even when they aren't needed.
       */

      if (!ascii_strcasecmp (p->attribute, "boundary")
          && !strcmp (buffer, tmp))
        snprintf (buffer, sizeof (buffer), "\"%s\"", tmp);

      p_delete(&tmp);

      tmplen = m_strlen(buffer) + m_strlen(p->attribute) + 1;

      if (len + tmplen + 2 > 76) {
        fputs ("\n\t", f);
        len = tmplen + 8;
      }
      else {
        fputc (' ', f);
        len += tmplen + 1;
      }

      fprintf (f, "%s%s=%s", p->attribute, encode ? "*" : "", buffer);

    }
  }

  fputc ('\n', f);

  if (a->description)
    fprintf (f, "Content-Description: %s\n", a->description);

  fprintf (f, "Content-Disposition: %s", DISPOSITION (a->disposition));

  if (a->use_disp) {
    if (!(fn = a->d_filename))
      fn = a->filename;

    if (fn) {
      char *tmp;

      /* Strip off the leading path... */
      if ((t = strrchr (fn, '/')))
        t++;
      else
        t = fn;

      buffer[0] = 0;
      tmp = m_strdup(t);
      encode = rfc2231_encode_string (&tmp);
      rfc822_strcpy(buffer, sizeof(buffer), tmp, MimeSpecials);
      p_delete(&tmp);
      fprintf (f, "; filename%s=%s", encode ? "*" : "", buffer);
    }
  }

  fputc ('\n', f);

  if (a->encoding != ENC7BIT)
    fprintf (f, "Content-Transfer-Encoding: %s\n", ENCODING (a->encoding));

  /* Do NOT add the terminator here!!! */
  return (ferror (f) ? -1 : 0);
}

# define write_as_text_part(a)  (mutt_is_text_part(a) || mutt_is_application_pgp(a))

int mutt_write_mime_body (BODY * a, FILE * f)
{
  char *p, boundary[SHORT_STRING];
  char send_charset[SHORT_STRING];
  FILE *fpin;
  BODY *t;
  FGETCONV *fc;

  if (a->type == TYPEMULTIPART) {
    /* First, find the boundary to use */
    if (!(p = mutt_get_parameter ("boundary", a->parameter))) {
      debug_print (1, ("no boundary parameter found!\n"));
      mutt_error _("No boundary parameter found! [report this error]");

      return (-1);
    }
    m_strcpy(boundary, sizeof(boundary), p);

    for (t = a->parts; t; t = t->next) {
      fprintf (f, "\n--%s\n", boundary);
      if (mutt_write_mime_header (t, f) == -1)
        return -1;
      fputc ('\n', f);
      if (mutt_write_mime_body (t, f) == -1)
        return -1;
    }
    fprintf (f, "\n--%s--\n", boundary);
    return (ferror (f) ? -1 : 0);
  }

  /* This is pretty gross, but it's the best solution for now... */
  if (a->type == TYPEAPPLICATION && !m_strcmp(a->subtype, "pgp-encrypted")) {
    fputs ("Version: 1\n", f);
    return 0;
  }

  if ((fpin = fopen (a->filename, "r")) == NULL) {
    debug_print (1, ("%s no longer exists!\n", a->filename));
    mutt_error (_("%s no longer exists!"), a->filename);
    return -1;
  }

  if (a->type == TYPETEXT && (!a->noconv))
    fc = fgetconv_open (fpin, a->file_charset,
                        mutt_get_body_charset (send_charset,
                                               sizeof (send_charset), a), 0);
  else
    fc = fgetconv_open (fpin, 0, 0, 0);

  if (a->encoding == ENCQUOTEDPRINTABLE)
    encode_quoted (fc, f, write_as_text_part (a));
  else if (a->encoding == ENCBASE64)
    encode_base64 (fc, f, write_as_text_part (a));
  else if (a->type == TYPETEXT && (!a->noconv))
    encode_8bit (fc, f, write_as_text_part (a));
  else
    mutt_copy_stream (fpin, f);

  fgetconv_close (&fc);
  fclose (fpin);

  return (ferror (f) ? -1 : 0);
}

#undef write_as_text_part

#define BOUNDARYLEN 16
void mutt_generate_boundary (PARAMETER ** parm)
{
  char rs[BOUNDARYLEN + 1];
  char *p = rs;
  int i;

  rs[BOUNDARYLEN] = 0;
  for (i = 0; i < BOUNDARYLEN; i++)
    *p++ = __m_b64chars[LRAND() % sizeof(__m_b64chars)];
  *p = 0;

  mutt_set_parameter ("boundary", rs, parm);
}

typedef struct {
  int from;
  int whitespace;
  int dot;
  int linelen;
  int was_cr;
} CONTENT_STATE;


static void update_content_info (CONTENT * info, CONTENT_STATE * s, char *d,
                                 size_t dlen)
{
  int from = s->from;
  int whitespace = s->whitespace;
  int dot = s->dot;
  int linelen = s->linelen;
  int was_cr = s->was_cr;

  if (!d) {                     /* This signals EOF */
    if (was_cr)
      info->binary = 1;
    if (linelen > info->linemax)
      info->linemax = linelen;

    return;
  }

  for (; dlen; d++, dlen--) {
    char ch = *d;

    if (was_cr) {
      was_cr = 0;
      if (ch != '\n') {
        info->binary = 1;
      }
      else {
        if (whitespace)
          info->space = 1;
        if (dot)
          info->dot = 1;
        if (linelen > info->linemax)
          info->linemax = linelen;
        whitespace = 0;
        dot = 0;
        linelen = 0;
        continue;
      }
    }

    linelen++;
    if (ch == '\n') {
      info->crlf++;
      if (whitespace)
        info->space = 1;
      if (dot)
        info->dot = 1;
      if (linelen > info->linemax)
        info->linemax = linelen;
      whitespace = 0;
      linelen = 0;
      dot = 0;
    }
    else if (ch == '\r') {
      info->crlf++;
      info->cr = 1;
      was_cr = 1;
      continue;
    }
    else if (ch & 0x80)
      info->hibin++;
    else if (ch == '\t' || ch == '\f') {
      info->ascii++;
      whitespace++;
    }
    else if (ch < 32 || ch == 127)
      info->lobin++;
    else {
      if (linelen == 1) {
        if ((ch == 'F') || (ch == 'f'))
          from = 1;
        else
          from = 0;
        if (ch == '.')
          dot = 1;
        else
          dot = 0;
      }
      else if (from) {
        if (linelen == 2 && ch != 'r')
          from = 0;
        else if (linelen == 3 && ch != 'o')
          from = 0;
        else if (linelen == 4) {
          if (ch == 'm')
            info->from = 1;
          from = 0;
        }
      }
      if (ch == ' ')
        whitespace++;
      info->ascii++;
    }

    if (linelen > 1)
      dot = 0;
    if (ch != ' ' && ch != '\t')
      whitespace = 0;
  }

  s->from = from;
  s->whitespace = whitespace;
  s->dot = dot;
  s->linelen = linelen;
  s->was_cr = was_cr;

}

/* Define as 1 if iconv sometimes returns -1(EILSEQ) instead of transcribing. */
#define BUGGY_ICONV 1

/*
 * Find the best charset conversion of the file from fromcode into one
 * of the tocodes. If successful, set *tocode and CONTENT *info and
 * return the number of characters converted inexactly. If no
 * conversion was possible, return -1.
 *
 * We convert via UTF-8 in order to avoid the condition -1(EINVAL),
 * which would otherwise prevent us from knowing the number of inexact
 * conversions. Where the candidate target charset is UTF-8 we avoid
 * doing the second conversion because iconv_open("UTF-8", "UTF-8")
 * fails with some libraries.
 *
 * We assume that the output from iconv is never more than 4 times as
 * long as the input for any pair of charsets we might be interested
 * in.
 */
static size_t convert_file_to (FILE * file, const char *fromcode,
                               int ncodes, const char **tocodes,
                               int *tocode, CONTENT * info)
{
#ifdef HAVE_ICONV
  iconv_t cd1, *cd;
  char bufi[256], bufu[512], bufo[4 * sizeof (bufi)];
  const char *ib, *ub;
  char *ob;
  size_t ibl, obl, ubl, ubl1, n, ret;
  int i;
  CONTENT *infos;
  CONTENT_STATE *states;
  size_t *score;

  cd1 = mutt_iconv_open ("UTF-8", fromcode, 0);
  if (cd1 == (iconv_t) (-1))
    return -1;

  cd = p_new(iconv_t, ncodes);
  score = p_new(size_t, ncodes);
  states = p_new(CONTENT_STATE, ncodes);
  infos = p_new(CONTENT, ncodes);

  for (i = 0; i < ncodes; i++)
    if (ascii_strcasecmp (tocodes[i], "UTF-8"))
      cd[i] = mutt_iconv_open (tocodes[i], "UTF-8", 0);
    else
      /* Special case for conversion to UTF-8 */
      cd[i] = (iconv_t) (-1), score[i] = (size_t) (-1);

  rewind (file);
  ibl = 0;
  for (;;) {

    /* Try to fill input buffer */
    n = fread (bufi + ibl, 1, sizeof (bufi) - ibl, file);
    ibl += n;

    /* Convert to UTF-8 */
    ib = bufi;
    ob = bufu, obl = sizeof (bufu);
    n = my_iconv(cd1, ibl ? &ib : 0, &ibl, &ob, &obl);
    assert (n == (size_t) (-1) || !n || ICONV_NONTRANS);
    if (n == (size_t) (-1) &&
        ((errno != EINVAL && errno != E2BIG) || ib == bufi)) {
      assert (errno == EILSEQ ||
              (errno == EINVAL && ib == bufi && ibl < sizeof (bufi)));
      ret = (size_t) (-1);
      break;
    }
    ubl1 = ob - bufu;

    /* Convert from UTF-8 */
    for (i = 0; i < ncodes; i++)
      if (cd[i] != (iconv_t) (-1) && score[i] != (size_t) (-1)) {
        ub = bufu, ubl = ubl1;
        ob = bufo, obl = sizeof (bufo);
        n = my_iconv(cd[i], (ibl || ubl) ? &ub : 0, &ubl, &ob, &obl);
        if (n == (size_t) (-1)) {
          assert (errno == E2BIG ||
                  (BUGGY_ICONV && (errno == EILSEQ || errno == ENOENT)));
          score[i] = (size_t) (-1);
        }
        else {
          score[i] += n;
          update_content_info (&infos[i], &states[i], bufo, ob - bufo);
        }
      }
      else if (cd[i] == (iconv_t) (-1) && score[i] == (size_t) (-1))
        /* Special case for conversion to UTF-8 */
        update_content_info (&infos[i], &states[i], bufu, ubl1);

    if (ibl)
      /* Save unused input */
      memmove (bufi, ib, ibl);
    else if (!ubl1 && ib < bufi + sizeof (bufi)) {
      ret = 0;
      break;
    }
  }

  if (!ret) {
    /* Find best score */
    ret = (size_t) (-1);
    for (i = 0; i < ncodes; i++) {
      if (cd[i] == (iconv_t) (-1) && score[i] == (size_t) (-1)) {
        /* Special case for conversion to UTF-8 */
        *tocode = i;
        ret = 0;
        break;
      }
      else if (cd[i] == (iconv_t) (-1) || score[i] == (size_t) (-1))
        continue;
      else if (ret == (size_t) (-1) || score[i] < ret) {
        *tocode = i;
        ret = score[i];
        if (!ret)
          break;
      }
    }
    if (ret != (size_t) (-1)) {
      memcpy (info, &infos[*tocode], sizeof (CONTENT));
      update_content_info (info, &states[*tocode], 0, 0);       /* EOF */
    }
  }

  for (i = 0; i < ncodes; i++)
    if (cd[i] != (iconv_t) (-1))
      iconv_close (cd[i]);

  iconv_close (cd1);
  p_delete(&cd);
  p_delete(&infos);
  p_delete(&score);
  p_delete(&states);

  return ret;
#else
  return -1;
#endif /* !HAVE_ICONV */
}

/*
 * Find the first of the fromcodes that gives a valid conversion and
 * the best charset conversion of the file into one of the tocodes. If
 * successful, set *fromcode and *tocode to dynamically allocated
 * strings, set CONTENT *info, and return the number of characters
 * converted inexactly. If no conversion was possible, return -1.
 *
 * Both fromcodes and tocodes may be colon-separated lists of charsets.
 * However, if fromcode is zero then fromcodes is assumed to be the
 * name of a single charset even if it contains a colon.
 */
static size_t convert_file_from_to (FILE * file,
                                    const char *fromcodes,
                                    const char *tocodes, char **fromcode,
                                    char **tocode, CONTENT * info)
{
  char *fcode;
  char **tcode;
  const char *c, *c1;
  size_t ret;
  int ncodes, i, cn;

  /* Count the tocodes */
  ncodes = 0;
  for (c = tocodes; c; c = c1 ? c1 + 1 : 0) {
    if ((c1 = strchr (c, ':')) == c)
      continue;
    ++ncodes;
  }

  /* Copy them */
  tcode = p_new(char *, ncodes);
  for (c = tocodes, i = 0; c; c = c1 ? c1 + 1 : 0, i++) {
    if ((c1 = strchr (c, ':')) == c)
      continue;
    tcode[i] = m_substrdup(c, c1);
  }

  ret = (size_t) (-1);
  if (fromcode) {
    /* Try each fromcode in turn */
    for (c = fromcodes; c; c = c1 ? c1 + 1 : 0) {
      if ((c1 = strchr (c, ':')) == c)
        continue;
      fcode = m_substrdup(c, c1);

      ret = convert_file_to (file, fcode, ncodes, (const char **) tcode,
                             &cn, info);
      if (ret != (size_t) (-1)) {
        *fromcode = fcode;
        *tocode = tcode[cn];
        tcode[cn] = 0;
        break;
      }
      p_delete(&fcode);
    }
  }
  else {
    /* There is only one fromcode */
    ret = convert_file_to (file, fromcodes, ncodes, (const char **) tcode,
                           &cn, info);
    if (ret != (size_t) (-1)) {
      *tocode = tcode[cn];
      tcode[cn] = 0;
    }
  }

  /* Free memory */
  for (i = 0; i < ncodes; i++)
    p_delete(&tcode[i]);

  p_delete(tcode);

  return ret;
}

/* 
 * Analyze the contents of a file to determine which MIME encoding to use.
 * Also set the body charset, sometimes, or not.
 */
CONTENT *mutt_get_content_info (const char *fname, BODY * b)
{
  CONTENT *info;
  CONTENT_STATE state;
  FILE *fp = NULL;
  char *fromcode = NULL;
  char *tocode = NULL;
  char buffer[100];
  char chsbuf[STRING];
  size_t r;

  struct stat sb;

  if (b && !fname)
    fname = b->filename;

  if (stat (fname, &sb) == -1) {
    mutt_error (_("Can't stat %s: %s"), fname, strerror (errno));
    return NULL;
  }

  if (!S_ISREG (sb.st_mode)) {
    mutt_error (_("%s isn't a regular file."), fname);
    return NULL;
  }

  if ((fp = fopen (fname, "r")) == NULL) {
    debug_print (1, ("%s: %s (errno %d).\n", fname, strerror (errno), errno));
    return (NULL);
  }

  info = p_new(CONTENT, 1);
  p_clear(&state, 1);

  if (b != NULL && b->type == TYPETEXT && (!b->noconv && !b->force_charset)) {
    char *chs = mutt_get_parameter ("charset", b->parameter);
    char *fchs = b->use_disp ? ((FileCharset && *FileCharset) ?
                                FileCharset : Charset) : Charset;
    if (Charset && (chs || SendCharset) &&
        convert_file_from_to (fp, fchs, chs ? chs : SendCharset,
                              &fromcode, &tocode, info) != (size_t) (-1)) {
      if (!chs) {
        mutt_canonical_charset (chsbuf, sizeof (chsbuf), tocode);
        mutt_set_parameter ("charset", chsbuf, &b->parameter);
      }
      b->file_charset = fromcode;
      p_delete(&tocode);
      safe_fclose (&fp);
      return info;
    }
  }

  rewind (fp);
  while ((r = fread (buffer, 1, sizeof (buffer), fp)))
    update_content_info (info, &state, buffer, r);
  update_content_info (info, &state, 0, 0);

  safe_fclose (&fp);

  if (b != NULL && b->type == TYPETEXT && (!b->noconv && !b->force_charset))
    mutt_set_parameter ("charset", (!info->hibin ? "us-ascii" :
                                    Charset
                                    && !mutt_is_us_ascii (Charset) ? Charset :
                                    "unknown-8bit"), &b->parameter);

  return info;
}

/* Given a file with path ``s'', see if there is a registered MIME type.
 * returns the major MIME type, and copies the subtype to ``d''.  First look
 * for ~/.mime.types, then look in a system mime.types if we can find one.
 * The longest match is used so that we can match `ps.gz' when `gz' also
 * exists.
 */

int mutt_lookup_mime_type (BODY * att, const char *path)
{
  FILE *f;
  char *p, *q, *ct;
  char buf[LONG_STRING];
  char subtype[STRING], xtype[STRING];
  int count;
  int szf, sze, cur_sze;
  int type;

  *subtype = '\0';
  *xtype = '\0';
  type = TYPEOTHER;
  cur_sze = 0;

  szf = m_strlen(path);

  for (count = 0; count < 4; count++) {
    /*
     * can't use strtok() because we use it in an inner loop below, so use
     * a switch statement here instead.
     */
    switch (count) {
    case 0:
      snprintf (buf, sizeof (buf), "%s/.mime.types", NONULL (Homedir));
      break;
    case 1:
      m_strcpy(buf, sizeof(buf), SYSCONFDIR "/madmutt-mime.types");
      break;
    case 2:
      m_strcpy(buf, sizeof(buf), PKGDATADIR "/mime.types");
      break;
    case 3:
      m_strcpy(buf, sizeof(buf), SYSCONFDIR "/mime.types");
      break;
    default:
      debug_print (1, ("Internal error, count = %d.\n", count));
      goto bye;                 /* shouldn't happen */
    }

    if ((f = fopen (buf, "r")) != NULL) {
      while (fgets (buf, sizeof (buf) - 1, f) != NULL) {
        /* weed out any comments */
        if ((p = strchr (buf, '#')))
          *p = 0;

        /* remove any leading space. */
        ct = vskipspaces(buf);

        /* position on the next field in this line */
        if ((p = strpbrk (ct, " \t")) == NULL)
          continue;
        *p++ = 0;
        p = vskipspaces(p);

        /* cycle through the file extensions */
        while ((p = strtok (p, " \t\n"))) {
          sze = m_strlen(p);
          if ((sze > cur_sze) && (szf >= sze) &&
              (m_strcasecmp(path + szf - sze, p) == 0
               || ascii_strcasecmp (path + szf - sze, p) == 0)
              && (szf == sze || path[szf - sze - 1] == '.'))
          {
            /* get the content-type */

            if ((p = strchr (ct, '/')) == NULL) {
              /* malformed line, just skip it. */
              break;
            }
            *p++ = 0;

            for (q = p; *q && !ISSPACE (*q); q++);

            m_strncpy(subtype, sizeof(subtype), p, q - p);

            if ((type = mutt_check_mime_type (ct)) == TYPEOTHER)
              m_strcpy(xtype, sizeof(xtype), ct);

            cur_sze = sze;
          }
          p = NULL;
        }
      }
      fclose (f);
    }
  }

bye:

  if (type != TYPEOTHER || *xtype != '\0') {
    att->type = type;
    m_strreplace(&att->subtype, subtype);
    m_strreplace(&att->xtype, xtype);
  }

  return (type);
}

void mutt_message_to_7bit (BODY * a, FILE * fp)
{
  char temp[_POSIX_PATH_MAX];
  char *line = NULL;
  FILE *fpin = NULL;
  FILE *fpout = NULL;
  struct stat sb;

  if (!a->filename && fp)
    fpin = fp;
  else if (!a->filename || !(fpin = fopen (a->filename, "r"))) {
    mutt_error (_("Could not open %s"), a->filename ? a->filename : "(null)");
    return;
  }
  else {
    a->offset = 0;
    if (stat (a->filename, &sb) == -1) {
      mutt_perror ("stat");
      fclose (fpin);
    }
    a->length = sb.st_size;
  }

  mutt_mktemp (temp);
  if (!(fpout = safe_fopen (temp, "w+"))) {
    mutt_perror ("fopen");
    goto cleanup;
  }

  fseeko (fpin, a->offset, 0);
  a->parts = mutt_parse_messageRFC822 (fpin, a);

  transform_to_7bit (a->parts, fpin);

  mutt_copy_hdr (fpin, fpout, a->offset, a->offset + a->length,
                 CH_MIME | CH_NONEWLINE | CH_XMIT, NULL);

  fputs ("MIME-Version: 1.0\n", fpout);
  mutt_write_mime_header (a->parts, fpout);
  fputc ('\n', fpout);
  mutt_write_mime_body (a->parts, fpout);

cleanup:
  p_delete(&line);

  if (fpin && !fp)
    fclose (fpin);
  if (fpout)
    fclose (fpout);
  else
    return;

  a->encoding = ENC7BIT;
  a->d_filename = a->filename;
  if (a->filename && a->unlink)
    unlink (a->filename);
  a->filename = m_strdup(temp);
  a->unlink = 1;
  if (stat (a->filename, &sb) == -1) {
    mutt_perror ("stat");
    return;
  }
  a->length = sb.st_size;
  mutt_free_body (&a->parts);
  a->hdr->content = NULL;
}

static void transform_to_7bit (BODY * a, FILE * fpin)
{
  char buff[_POSIX_PATH_MAX];
  STATE s;
  struct stat sb;

  p_clear(&s, 1);
  for (; a; a = a->next) {
    if (a->type == TYPEMULTIPART) {
      if (a->encoding != ENC7BIT)
        a->encoding = ENC7BIT;

      transform_to_7bit (a->parts, fpin);
    }
    else if (mutt_is_message_type (a->type, a->subtype)) {
      mutt_message_to_7bit (a, fpin);
    }
    else {
      a->noconv = 1;
      a->force_charset = 1;

      mutt_mktemp (buff);
      if ((s.fpout = safe_fopen (buff, "w")) == NULL) {
        mutt_perror ("fopen");
        return;
      }
      s.fpin = fpin;
      mutt_decode_attachment (a, &s);
      fclose (s.fpout);
      a->d_filename = a->filename;
      a->filename = m_strdup(buff);
      a->unlink = 1;
      if (stat (a->filename, &sb) == -1) {
        mutt_perror ("stat");
        return;
      }
      a->length = sb.st_size;

      mutt_update_encoding (a);
      if (a->encoding == ENC8BIT)
        a->encoding = ENCQUOTEDPRINTABLE;
      else if (a->encoding == ENCBINARY)
        a->encoding = ENCBASE64;
    }
  }
}

/* determine which Content-Transfer-Encoding to use */
static void mutt_set_encoding (BODY * b, CONTENT * info)
{
  char send_charset[SHORT_STRING];

  if (b->type == TYPETEXT) {
    char *chsname =
      mutt_get_body_charset (send_charset, sizeof (send_charset), b);
    if ((info->lobin && ascii_strncasecmp (chsname, "iso-2022", 8))
        || info->linemax > 990 || (info->from && option (OPTENCODEFROM)))
      b->encoding = ENCQUOTEDPRINTABLE;
    else if (info->hibin)
      b->encoding = option (OPTALLOW8BIT) ? ENC8BIT : ENCQUOTEDPRINTABLE;
    else
      b->encoding = ENC7BIT;
  }
  else if (b->type == TYPEMESSAGE || b->type == TYPEMULTIPART) {
    if (info->lobin || info->hibin) {
      if (option (OPTALLOW8BIT) && !info->lobin)
        b->encoding = ENC8BIT;
      else
        mutt_message_to_7bit (b, NULL);
    }
    else
      b->encoding = ENC7BIT;
  }
  else if (b->type == TYPEAPPLICATION
           && ascii_strcasecmp (b->subtype, "pgp-keys") == 0)
    b->encoding = ENC7BIT;
  else
#if 0
  if (info->lobin || info->hibin || info->binary || info->linemax > 990
        || info->cr || ( /* option (OPTENCODEFROM) && */ info->from))
#endif
  {
    /* Determine which encoding is smaller  */
    if (1.33 * (float) (info->lobin + info->hibin + info->ascii) <
        3.0 * (float) (info->lobin + info->hibin) + (float) info->ascii)
      b->encoding = ENCBASE64;
    else
      b->encoding = ENCQUOTEDPRINTABLE;
  }
#if 0
  else
    b->encoding = ENC7BIT;
#endif
}

void mutt_stamp_attachment (BODY * a)
{
  a->stamp = time (NULL);
}

/* Get a body's character set */

char *mutt_get_body_charset (char *d, size_t dlen, BODY * b)
{
  char *p = NULL;

  if (b && b->type != TYPETEXT)
    return NULL;

  if (b)
    p = mutt_get_parameter ("charset", b->parameter);

  if (p)
    mutt_canonical_charset (d, dlen, NONULL (p));
  else
    m_strcpy(d, dlen, "us-ascii");

  return d;
}


/* Assumes called from send mode where BODY->filename points to actual file */
void mutt_update_encoding (BODY * a)
{
  CONTENT *info;
  char chsbuff[STRING];

  /* override noconv when it's us-ascii */
  if (mutt_is_us_ascii (mutt_get_body_charset (chsbuff, sizeof (chsbuff), a)))
    a->noconv = 0;

  if (!a->force_charset && !a->noconv)
    mutt_delete_parameter ("charset", &a->parameter);

  if ((info = mutt_get_content_info (a->filename, a)) == NULL)
    return;

  mutt_set_encoding (a, info);
  mutt_stamp_attachment (a);

  p_delete(&a->content);
  a->content = info;

}

BODY *mutt_make_message_attach (CONTEXT * ctx, HEADER * hdr, int attach_msg)
{
  char buffer[LONG_STRING];
  BODY *body;
  FILE *fp;
  int cmflags, chflags;
  int pgp = hdr->security;

  if ((option (OPTMIMEFORWDECODE) || option (OPTFORWDECRYPT)) &&
      (hdr->security & ENCRYPT)) {
    if (!crypt_valid_passphrase (hdr->security))
      return (NULL);
  }

  mutt_mktemp (buffer);
  if ((fp = safe_fopen (buffer, "w+")) == NULL)
    return NULL;

  body = mutt_new_body ();
  body->type = TYPEMESSAGE;
  body->subtype = m_strdup("rfc822");
  body->filename = m_strdup(buffer);
  body->unlink = 1;
  body->use_disp = 0;
  body->disposition = DISPINLINE;
  body->noconv = 1;

  mutt_parse_mime_message (ctx, hdr);

  chflags = CH_XMIT;
  cmflags = 0;

  /* If we are attaching a message, ignore OPTMIMEFORWDECODE */
  if (!attach_msg && option (OPTMIMEFORWDECODE)) {
    chflags |= CH_MIME | CH_TXTPLAIN;
    cmflags = M_CM_DECODE | M_CM_CHARCONV;
    pgp &= ~(PGPENCRYPT|SMIMEENCRYPT);
  }
  else if (option (OPTFORWDECRYPT) && (hdr->security & ENCRYPT)) {
    if (mutt_is_multipart_encrypted (hdr->content)) {
      chflags |= CH_MIME | CH_NONEWLINE;
      cmflags = M_CM_DECODE_PGP;
      pgp &= ~PGPENCRYPT;
    }
    else if (mutt_is_application_pgp (hdr->content) & PGPENCRYPT) {
      chflags |= CH_MIME | CH_TXTPLAIN;
      cmflags = M_CM_DECODE | M_CM_CHARCONV;
      pgp &= ~PGPENCRYPT;
    }
    else if (mutt_is_application_smime (hdr->content) & SMIMEENCRYPT) {
      chflags |= CH_MIME | CH_TXTPLAIN;
      cmflags = M_CM_DECODE | M_CM_CHARCONV;
      pgp &= ~SMIMEENCRYPT;
    }
  }

  mutt_copy_message (fp, ctx, hdr, cmflags, chflags);

  fflush (fp);
  rewind (fp);

  body->hdr = header_new();
  body->hdr->offset = 0;
  /* we don't need the user headers here */
  body->hdr->env = mutt_read_rfc822_header (fp, body->hdr, 0, 0);
  body->hdr->security = pgp;
  mutt_update_encoding (body);
  body->parts = body->hdr->content;

  fclose (fp);

  return (body);
}

BODY *mutt_make_file_attach (const char *path)
{
  BODY *att;
  CONTENT *info;

  att = mutt_new_body ();
  att->filename = m_strdup(path);

  /* Attempt to determine the appropriate content-type based on the filename
   * suffix.
   */

#if 0

  if ((n =
       mutt_lookup_mime_type (buf, sizeof (buf), xbuf, sizeof (xbuf),
                              path)) != TYPEOTHER || *xbuf != '\0') {
    att->type = n;
    att->subtype = m_strdup(buf);
    att->xtype = m_strdup(xbuf);
  }

#else

  mutt_lookup_mime_type (att, path);

#endif

  if ((info = mutt_get_content_info (path, att)) == NULL) {
    mutt_free_body (&att);
    return NULL;
  }

  if (!att->subtype) {
    if (info->lobin == 0
        || (info->lobin + info->hibin + info->ascii) / info->lobin >= 10) {
      /*
       * Statistically speaking, there should be more than 10% "lobin" 
       * chars if this is really a binary file...
       */
      att->type = TYPETEXT;
      att->subtype = m_strdup("plain");
    }
    else {
      att->type = TYPEAPPLICATION;
      att->subtype = m_strdup("octet-stream");
    }
  }

  mutt_update_encoding (att);
  return (att);
}

static int get_toplevel_encoding (BODY * a)
{
  int e = ENC7BIT;

  for (; a; a = a->next) {
    if (a->encoding == ENCBINARY)
      return (ENCBINARY);
    else if (a->encoding == ENC8BIT)
      e = ENC8BIT;
  }

  return (e);
}

BODY *mutt_make_multipart (BODY * b)
{
  BODY *new;

  new = mutt_new_body ();
  new->type = TYPEMULTIPART;
  new->subtype = m_strdup("mixed");
  new->encoding = get_toplevel_encoding (b);
  mutt_generate_boundary (&new->parameter);
  new->use_disp = 0;
  new->disposition = DISPINLINE;
  new->parts = b;

  return new;
}

/* remove the multipart body if it exists */
BODY *mutt_remove_multipart (BODY * b)
{
  BODY *t;

  if (b->parts) {
    t = b;
    b = b->parts;
    t->parts = NULL;
    mutt_free_body (&t);
  }
  return b;
}

char *mutt_make_date (char *s, size_t len)
{
  time_t t = time (NULL);
  struct tm *l = localtime (&t);
  time_t tz = mutt_local_tz (t);

  tz /= 60;

  snprintf (s, len, "Date: %s, %d %s %d %02d:%02d:%02d %+03d%02d\n",
            Weekdays[l->tm_wday], l->tm_mday, Months[l->tm_mon],
            l->tm_year + 1900, l->tm_hour, l->tm_min, l->tm_sec,
            (int) tz / 60, (int) abs (tz) % 60);
  return (s);
}

/* wrapper around mutt_write_address() so we can handle very large
   recipient lists without needing a huge temporary buffer in memory */
void mutt_write_address_list (address_t * adr, FILE * fp, int linelen,
                              int display)
{
  address_t *tmp;
  char buf[LONG_STRING];
  int count = 0;
  int len;

  while (adr) {
    tmp = adr->next;
    adr->next = NULL;
    buf[0] = 0;
    rfc822_write_address (buf, sizeof (buf), adr, display);
    len = m_strlen(buf);
    if (count && linelen + len > 74) {
      fputs ("\n\t", fp);
      linelen = len + 8;        /* tab is usually about 8 spaces... */
    }
    else {
      if (count && adr->mailbox) {
        fputc (' ', fp);
        linelen++;
      }
      linelen += len;
    }
    fputs (buf, fp);
    adr->next = tmp;
    if (!adr->group && adr->next && adr->next->mailbox) {
      linelen++;
      fputc (',', fp);
    }
    adr = adr->next;
    count++;
  }
  fputc ('\n', fp);
}

/* arbitrary number of elements to grow the array by */
#define REF_INC 16

#define TrimRef 10

/* need to write the list in reverse because they are stored in reverse order
 * when parsed to speed up threading
 */
void mutt_write_references (LIST * r, FILE * f)
{
  LIST **ref = NULL;
  int refcnt = 0, refmax = 0;

  for (; (TrimRef == 0 || refcnt < TrimRef) && r; r = r->next) {
    if (refcnt == refmax)
      p_realloc(&ref, refmax += REF_INC);
    ref[refcnt++] = r;
  }

  while (refcnt-- > 0) {
    fputc (' ', f);
    fputs (ref[refcnt]->data, f);
  }

  p_delete(&ref);
}

/* Note: all RFC2047 encoding should be done outside of this routine, except
 * for the "real name."  This will allow this routine to be used more than
 * once, if necessary.
 * 
 * Likewise, all IDN processing should happen outside of this routine.
 *
 * mode == 1  => "lite" mode (used for edit_hdrs)
 * mode == 0  => normal mode.  write full header + MIME headers
 * mode == -1 => write just the envelope info (used for postponing messages)
 * 
 * privacy != 0 => will omit any headers which may identify the user.
 *               Output generated is suitable for being sent through
 *               anonymous remailer chains.
 *
 */

int mutt_write_rfc822_header (FILE * fp, ENVELOPE * env, BODY * attach,
                              int mode, int privacy)
{
  char buffer[LONG_STRING];
  char *p;
  LIST *tmp = env->userhdrs;
  int has_agent = 0;            /* user defined user-agent header field exists */
  list2_t* hdrs = list_from_str (EditorHeaders, " ");

#ifdef USE_NNTP
  if (!option (OPTNEWSSEND))
#endif
    if (mode == 0 && !privacy)
      fputs (mutt_make_date (buffer, sizeof (buffer)), fp);

#define EDIT_HEADER(x) (mode != 1 || option(OPTXMAILTO) || (mode == 1 && list_lookup(hdrs,(list_lookup_t*) ascii_strcasecmp,x) >= 0))

  /* OPTUSEFROM is not consulted here so that we can still write a From:
   * field if the user sets it with the `my_hdr' command
   */
  if (env->from && !privacy) {
    buffer[0] = 0;
    rfc822_write_address (buffer, sizeof (buffer), env->from, 0);
    fprintf (fp, "From: %s\n", buffer);
  }

  if (env->to) {
    fputs ("To: ", fp);
    mutt_write_address_list (env->to, fp, 4, 0);
  }
  else if (mode > 0)
#ifdef USE_NNTP
    if (!option (OPTNEWSSEND))
#endif
      if (EDIT_HEADER("To:"))
        fputs ("To:\n", fp);

  if (env->cc) {
    fputs ("Cc: ", fp);
    mutt_write_address_list (env->cc, fp, 4, 0);
  }
  else if (mode > 0)
#ifdef USE_NNTP
    if (!option (OPTNEWSSEND))
#endif
      if (EDIT_HEADER("Cc:"))
        fputs ("Cc:\n", fp);

  if (env->bcc) {
    if (mode != 0 || option (OPTWRITEBCC)) {
      fputs ("Bcc: ", fp);
      mutt_write_address_list (env->bcc, fp, 5, 0);
    }
  }
  else if (mode > 0)
#ifdef USE_NNTP
    if (!option (OPTNEWSSEND))
#endif
      if (EDIT_HEADER("Bcc:"))
        fputs ("Bcc:\n", fp);

#ifdef USE_NNTP
  if (env->newsgroups)
    fprintf (fp, "Newsgroups: %s\n", env->newsgroups);
  else if (mode == 1 && option (OPTNEWSSEND) && EDIT_HEADER("Newsgroups:"))
    fputs ("Newsgroups:\n", fp);

  if (env->followup_to)
    fprintf (fp, "Followup-To: %s\n", env->followup_to);
  else if (mode == 1 && option (OPTNEWSSEND) && EDIT_HEADER("Followup-To:"))
    fputs ("Followup-To:\n", fp);

  if (env->x_comment_to)
    fprintf (fp, "X-Comment-To: %s\n", env->x_comment_to);
  else if (mode == 1 && option (OPTNEWSSEND) && option (OPTXCOMMENTTO) &&
           EDIT_HEADER("X-Comment-To:"))
    fputs ("X-Comment-To:\n", fp);
#endif

  if (env->subject)
    fprintf (fp, "Subject: %s\n", env->subject);
  else if (mode == 1 && EDIT_HEADER("Subject:"))
    fputs ("Subject:\n", fp);

  /* save message id if the user has set it */
  if (env->message_id && !privacy)
    fprintf (fp, "Message-ID: %s\n", env->message_id);

  if (env->reply_to) {
    fputs ("Reply-To: ", fp);
    mutt_write_address_list (env->reply_to, fp, 10, 0);
  }
  else if (mode > 0 && EDIT_HEADER("Reply-To:"))
    fputs ("Reply-To:\n", fp);

  if (env->mail_followup_to)
#ifdef USE_NNTP
    if (!option (OPTNEWSSEND))
#endif
    {
      fputs ("Mail-Followup-To: ", fp);
      mutt_write_address_list (env->mail_followup_to, fp, 18, 0);
    }

  if (mode <= 0) {
    if (env->references) {
      fputs ("References:", fp);
      mutt_write_references (env->references, fp);
      fputc ('\n', fp);
    }

    /* Add the MIME headers */
    fputs ("MIME-Version: 1.0\n", fp);
    mutt_write_mime_header (attach, fp);
  }

  if (env->in_reply_to) {
    fputs ("In-Reply-To:", fp);
    mutt_write_references (env->in_reply_to, fp);
    fputc ('\n', fp);
  }

#undef EDIT_HEADER

  /* Add any user defined headers */
  for (; tmp; tmp = tmp->next) {
    if ((p = strchr (tmp->data, ':'))) {
      p = vskipspaces(p + 1);
      if (!*p)
        continue;               /* don't emit empty fields. */

      /* check to see if the user has overridden the user-agent field */
      if (!ascii_strncasecmp ("user-agent", tmp->data, 10)) {
        has_agent = 1;
        if (privacy)
          continue;
      }

      fputs (tmp->data, fp);
      fputc ('\n', fp);
    }
  }

  if (mode == 0 && !privacy && option (OPTXMAILER) && !has_agent) {
    const char *os;

    if (OperatingSystem != NULL) {
      os = OperatingSystem;
    } else {
      struct utsname un;
      os = (uname(&un) == -1) ? "UNIX" : un.sysname;
    }
    /* Add a vanity header */
    fprintf (fp, "User-Agent: %s (%s)\n", mutt_make_version (0), os);
  }

  list_del (&hdrs, (list_del_t*)xmemfree);

  return (ferror (fp) == 0 ? 0 : -1);
}

static void encode_headers (LIST * h)
{
  char *tmp;
  char *p;
  int i;

  for (; h; h = h->next) {
    if (!(p = strchr (h->data, ':')))
      continue;

    i = p - h->data;
    p = vskipspaces(p + 1);
    tmp = m_strdup(p);

    if (!tmp)
      continue;

    rfc2047_encode_string (&tmp);
    p_realloc(&h->data, m_strlen(h->data) + 2 + m_strlen(tmp) + 1);

    sprintf (h->data + i, ": %s", NONULL (tmp));        /* __SPRINTF_CHECKED__ */

    p_delete(&tmp);
  }
}

const char *mutt_fqdn (short may_hide_host)
{
  char *p = NULL, *q;

  if (Fqdn && Fqdn[0] != '@') {
    p = Fqdn;

    if (may_hide_host && option (OPTHIDDENHOST)) {
      if ((p = strchr (Fqdn, '.')))
        p++;

      /* sanity check: don't hide the host if
       * the fqdn is something like detebe.org.
       */

      if (!p || !(q = strchr (p, '.')))
        p = Fqdn;
    }
  }

  return p;
}

/* normalized character (we're stricter than RFC2822, 3.6.4) */
static char mutt_normalized_char(char c)
{
    return (isalnum(c) || strchr(".!#$%&'*+-/=?^_`{|}~", c)) ? c : '.';
}

static void mutt_gen_localpart(char *buf, unsigned int len, const char *fmt)
{
#define APPEND_FMT(fmt, arg) \
        if (len > 1) {                                  \
            int snlen = snprintf(buf, len, fmt, arg);   \
            buf += snlen;                               \
            len -= snlen;                               \
        }

#define APPEND_BYTE(c) \
        if (len > 1) {                                  \
            *buf++ = c;                                 \
            *buf   = '\0';                              \
            len--;                                      \
        }

    time_t now;
    struct tm *tm;

    now = time (NULL);
    tm = gmtime (&now);

    while (*fmt) {
        int c = *fmt++;

        if (c != '%') {
            APPEND_BYTE(mutt_normalized_char(c));
            continue;
        }

        switch (*fmt++) {
          case 0:
            return;
          case 'd':
            APPEND_FMT("%02d", tm->tm_mday);
            break;
          case 'h':
            APPEND_FMT("%02d", tm->tm_hour);
            break;
          case 'm':
            APPEND_FMT("%02d", tm->tm_mon + 1);
            break;
          case 'M':
            APPEND_FMT("%02d", tm->tm_min);
            break;
          case 'O':
            APPEND_FMT("%lo", (unsigned long)now);
            break;
          case 'p':
            APPEND_FMT("%u", (unsigned int)getpid());
            break;
          case 'P':
            APPEND_FMT("%c", MsgIdPfx);
            MsgIdPfx = (MsgIdPfx == 'Z') ? 'A' : MsgIdPfx + 1;
            break;
          case 'r':
            APPEND_FMT("%u", (unsigned int)rand());
            break;
          case 'R':
            APPEND_FMT("%x", (unsigned int)rand());
            break;
          case 's':
            APPEND_FMT("%02d", tm->tm_sec);
            break;
          case 'T':
            APPEND_FMT("%u", (unsigned int) now);
            break;
          case 'X':
            APPEND_FMT("%x", (unsigned int) now);
            break;
          case 'Y':       /* this will break in the year 10000 ;-) */
            APPEND_FMT("%04d", tm->tm_year + 1900);
            break;
          case '%':
            APPEND_BYTE('%');
            break;
          default:       /* invalid formats are replaced by '.' */
            APPEND_BYTE('.');
            m_strncat(buf, len, ".", 1); 
        }
    }

    *buf = '\0';

#undef APPEND_BYTE
#undef APPEND_FMT
}

char *mutt_gen_msgid (void)
{
  char buf[SHORT_STRING];
  char localpart[SHORT_STRING];
  unsigned int localpart_length;
  const char *fqdn;

  if (!(fqdn = mutt_fqdn (0)))
    fqdn = NONULL (Hostname);

  localpart_length = sizeof (buf) - m_strlen(fqdn) - 4;  /* the 4 characters are '<', '@', '>' and '\0' */

  mutt_gen_localpart (localpart, localpart_length, MsgIdFormat);

  snprintf (buf, sizeof (buf), "<%s@%s>", localpart, fqdn);
  return (m_strdup(buf));
}

static RETSIGTYPE alarm_handler (int sig)
{
  SigAlrm = 1;
}

/* invoke sendmail in a subshell
   path (in)            path to program to execute
   args (in)            arguments to pass to program
   msg (in)             temp file containing message to send
   tempfile (out)       if sendmail is put in the background, this points
                        to the temporary file containing the stdout of the
                        child process */
static int
send_msg(const char *path, const char **args, const char *msg, char **tempfile)
{
  sigset_t set;
  int fd, st;
  pid_t pid, ppid;

  mutt_block_signals_system ();

  sigemptyset (&set);
  /* we also don't want to be stopped right now */
  sigaddset (&set, SIGTSTP);
  sigprocmask (SIG_BLOCK, &set, NULL);

  if (SendmailWait >= 0) {
    char tmp[_POSIX_PATH_MAX];

    mutt_mktemp (tmp);
    *tempfile = m_strdup(tmp);
  }

  if ((pid = fork ()) == 0) {
    struct sigaction act, oldalrm;

    /* save parent's ID before setsid() */
    ppid = getppid ();

    /* we want the delivery to continue even after the main process dies,
     * so we put ourselves into another session right away
     */
    setsid ();

    /* next we close all open files */
#if defined(OPEN_MAX)
    for (fd = 0; fd < OPEN_MAX; fd++)
      close (fd);
#elif defined(_POSIX_OPEN_MAX)
    for (fd = 0; fd < _POSIX_OPEN_MAX; fd++)
      close (fd);
#else
    close (0);
    close (1);
    close (2);
#endif

    /* now the second fork() */
    if ((pid = fork ()) == 0) {
      /* "msg" will be opened as stdin */
      if (open (msg, O_RDONLY, 0) < 0) {
        unlink (msg);
        _exit (S_ERR);
      }
      unlink (msg);

      if (SendmailWait >= 0) {
        /* *tempfile will be opened as stdout */
        if (open (*tempfile, O_WRONLY | O_APPEND | O_CREAT | O_EXCL, 0600) <
            0)
          _exit (S_ERR);
        /* redirect stderr to *tempfile too */
        if (dup (1) < 0)
          _exit (S_ERR);
      }
      else {
        if (open ("/dev/null", O_WRONLY | O_APPEND) < 0)        /* stdout */
          _exit (S_ERR);
        if (open ("/dev/null", O_RDWR | O_APPEND) < 0)  /* stderr */
          _exit (S_ERR);
      }

      execv (path, args);
      _exit (S_ERR);
    }
    else if (pid == -1) {
      unlink (msg);
      p_delete(tempfile);
      _exit (S_ERR);
    }

    /* SendmailWait > 0: interrupt waitpid() after SendmailWait seconds
     * SendmailWait = 0: wait forever
     * SendmailWait < 0: don't wait
     */
    if (SendmailWait > 0) {
      SigAlrm = 0;
      act.sa_handler = alarm_handler;
#ifdef SA_INTERRUPT
      /* need to make sure waitpid() is interrupted on SIGALRM */
      act.sa_flags = SA_INTERRUPT;
#else
      act.sa_flags = 0;
#endif
      sigemptyset (&act.sa_mask);
      sigaction (SIGALRM, &act, &oldalrm);
      alarm (SendmailWait);
    }
    else if (SendmailWait < 0)
      _exit (0xff & EX_OK);

    if (waitpid (pid, &st, 0) > 0) {
      st = WIFEXITED (st) ? WEXITSTATUS (st) : S_ERR;
      if (SendmailWait && st == (0xff & EX_OK)) {
        unlink (*tempfile);     /* no longer needed */
        p_delete(tempfile);
      }
    }
    else {
      st = (SendmailWait > 0 && errno == EINTR && SigAlrm) ? S_BKG : S_ERR;
      if (SendmailWait > 0) {
        unlink (*tempfile);
        p_delete(tempfile);
      }
    }

    /* reset alarm; not really needed, but... */
    alarm (0);
    sigaction (SIGALRM, &oldalrm, NULL);

    if (kill (ppid, 0) == -1 && errno == ESRCH) {
      /* the parent is already dead */
      unlink (*tempfile);
      p_delete(tempfile);
    }

    _exit (st);
  }

  sigprocmask (SIG_UNBLOCK, &set, NULL);

  if (pid != -1 && waitpid (pid, &st, 0) > 0)
    st = WIFEXITED (st) ? WEXITSTATUS (st) : S_ERR;     /* return child status */
  else
    st = S_ERR;                 /* error */

  mutt_unblock_signals_system (1);

  return (st);
}

static const char **
add_args(const char **args, size_t *argslen, size_t *argsmax, address_t * addr)
{
  for (; addr; addr = addr->next) {
    /* weed out group mailboxes, since those are for display only */
    if (addr->mailbox && !addr->group) {
      if (*argslen == *argsmax)
        p_realloc(&args, *argsmax += 5);
      args[(*argslen)++] = addr->mailbox;
    }
  }
  return (args);
}

static const char **
add_option(const char **args, size_t *argslen, size_t *argsmax, const char *s)
{
    if (*argslen == *argsmax) {
        p_realloc(&args, *argsmax += 5);
    }
    args[(*argslen)++] = s;
    return (args);
}

static int mutt_invoke_sendmail (address_t * from,        /* the sender */
                                 address_t * to, address_t * cc, address_t * bcc,     /* recips */
                                 const char *msg,       /* file containing message */
                                 int eightbit)
{                               /* message contains 8bit chars */
  char *ps = NULL, *path = NULL, *s = NULL, *childout = NULL;
  const char **args = NULL;
  size_t argslen = 0, argsmax = 0;
  int i;

#ifdef USE_NNTP
  if (option (OPTNEWSSEND)) {
    char cmd[LONG_STRING];

    mutt_FormatString (cmd, sizeof (cmd), NONULL (Inews), nntp_format_str, 0,
                       0);
    if (!*cmd) {
      i = nntp_post (msg);
      unlink (msg);
      return i;
    }

    s = m_strdup(cmd);
  }
  else
#endif
    s = m_strdup(Sendmail);

  ps = s;
  i = 0;
  while ((ps = strtok (ps, " "))) {
    if (argslen == argsmax)
      p_realloc(&args, argsmax += 5);

    if (i)
      args[argslen++] = ps;
    else {
      path = m_strdup(ps);
      ps = strrchr (ps, '/');
      if (ps)
        ps++;
      else
        ps = path;
      args[argslen++] = ps;
    }
    ps = NULL;
    i++;
  }

#ifdef USE_NNTP
  if (!option (OPTNEWSSEND)) {
#endif
    if (eightbit && option (OPTUSE8BITMIME))
      args = add_option(args, &argslen, &argsmax, "-B8BITMIME");

    if (option (OPTENVFROM)) {
      address_t *f = NULL;
      if (EnvFrom)
        f = EnvFrom;
      else if (from && !from->next)
        f = from;
      if (f) {
        args = add_option (args, &argslen, &argsmax, "-f");
        args = add_args (args, &argslen, &argsmax, f);
      }
    }
    if (DsnNotify) {
      args = add_option (args, &argslen, &argsmax, "-N");
      args = add_option (args, &argslen, &argsmax, DsnNotify);
    }
    if (DsnReturn) {
      args = add_option (args, &argslen, &argsmax, "-R");
      args = add_option (args, &argslen, &argsmax, DsnReturn);
    }
    args = add_option (args, &argslen, &argsmax, "--");
    args = add_args (args, &argslen, &argsmax, to);
    args = add_args (args, &argslen, &argsmax, cc);
    args = add_args (args, &argslen, &argsmax, bcc);
#ifdef USE_NNTP
  }
#endif

  if (argslen == argsmax)
    p_realloc(&args, ++argsmax);

  args[argslen++] = NULL;

  if ((i = send_msg (path, args, msg, &childout)) != (EX_OK & 0xff)) {
    if (i != S_BKG) {
      const char *e = mutt_strsysexit (i);

      e = mutt_strsysexit (i);
      mutt_error (_("Error sending message, child exited %d (%s)."), i,
                  NONULL (e));
      if (childout) {
        struct stat st;

        if (stat (childout, &st) == 0 && st.st_size > 0)
          mutt_do_pager (_("Output of the delivery process"), childout, 0,
                         NULL);
      }
    }
  }
  else
    unlink (childout);

  p_delete(&childout);
  p_delete(&path);
  p_delete(&s);
  p_delete(&args);

  if (i == (EX_OK & 0xff))
    i = 0;
  else if (i == S_BKG)
    i = 1;
  else
    i = -1;
  return (i);
}

int mutt_invoke_mta (address_t * from,    /* the sender */
                     address_t * to, address_t * cc, address_t * bcc, /* recips */
                     const char *msg,   /* file containing message */
                     int eightbit)
{                               /* message contains 8bit chars */
#ifdef USE_LIBESMTP
#ifdef USE_NNTP
  if (!option (OPTNEWSSEND))
#endif
    if (SmtpHost)
      return mutt_libesmtp_invoke (from, to, cc, bcc, msg, eightbit);
#endif

  return mutt_invoke_sendmail (from, to, cc, bcc, msg, eightbit);
}

/* appends string 'b' to string 'a', and returns the pointer to the new
   string. */
char *mutt_append_string (char *a, const char *b)
{
  size_t la = m_strlen(a);

  p_realloc(&a, la + m_strlen(b) + 1);
  strcpy (a + la, b);           /* __STRCPY_CHECKED__ */
  return (a);
}

/* returns 1 if char `c' needs to be quoted to protect from shell
   interpretation when executing commands in a subshell */
#define INVALID_CHAR(c) (!isalnum ((unsigned char)c) && !strchr ("@.+-_,:", c))

/* returns 1 if string `s' contains characters which could cause problems
   when used on a command line to execute a command */
int mutt_needs_quote (const char *s)
{
  while (*s) {
    if (INVALID_CHAR (*s))
      return 1;
    s++;
  }
  return 0;
}

/* Quote a string to prevent shell escapes when this string is used on the
   command line to send mail. */
char *mutt_quote_string (const char *s)
{
  char *r, *pr;
  size_t rlen;

  rlen = m_strlen(s) + 3;
  pr = r = p_new(char, rlen);
  *pr++ = '"';
  while (*s) {
    if (INVALID_CHAR (*s)) {
      size_t o = pr - r;

      p_realloc(&r, ++rlen);
      pr = r + o;
      *pr++ = '\\';
    }
    *pr++ = *s++;
  }
  *pr++ = '"';
  *pr = 0;
  return (r);
}

/* For postponing (!final) do the necessary encodings only */
void mutt_prepare_envelope (ENVELOPE * env, int final)
{
  char buffer[LONG_STRING];

  if (final) {
    if (env->bcc && !(env->to || env->cc)) {
      /* some MTA's will put an Apparently-To: header field showing the Bcc:
       * recipients if there is no To: or Cc: field, so attempt to suppress
       * it by using an empty To: field.
       */
      env->to = address_new ();
      env->to->group = 1;
      env->to->next = address_new ();

      buffer[0] = 0;
      rfc822_strcpy(buffer, sizeof(buffer), "undisclosed-recipients",
                    RFC822Specials);

      env->to->mailbox = m_strdup(buffer);
    }

    mutt_set_followup_to (env);

    if (!env->message_id && MsgIdFormat && *MsgIdFormat)
      env->message_id = mutt_gen_msgid ();
  }

  /* Take care of 8-bit => 7-bit conversion. */
  rfc2047_encode_adrlist (env->to, "To");
  rfc2047_encode_adrlist (env->cc, "Cc");
  rfc2047_encode_adrlist (env->bcc, "Bcc");
  rfc2047_encode_adrlist (env->from, "From");
  rfc2047_encode_adrlist (env->mail_followup_to, "Mail-Followup-To");
  rfc2047_encode_adrlist (env->reply_to, "Reply-To");

  if (env->subject)
#ifdef USE_NNTP
    if (!option (OPTNEWSSEND) || option (OPTMIMESUBJECT))
#endif
    {
      rfc2047_encode_string (&env->subject);
    }
  encode_headers (env->userhdrs);
}

void mutt_unprepare_envelope (ENVELOPE * env)
{
  LIST *item;

  for (item = env->userhdrs; item; item = item->next)
    rfc2047_decode (&item->data);

  address_delete (&env->mail_followup_to);

  /* back conversions */
  rfc2047_decode_adrlist (env->to);
  rfc2047_decode_adrlist (env->cc);
  rfc2047_decode_adrlist (env->bcc);
  rfc2047_decode_adrlist (env->from);
  rfc2047_decode_adrlist (env->reply_to);
  rfc2047_decode (&env->subject);
}

static int _mutt_bounce_message (FILE * fp, HEADER * h, address_t * to,
                                 const char *resent_from, address_t * env_from)
{
  int i, ret = 0;
  FILE *f;
  char date[SHORT_STRING], tempfile[_POSIX_PATH_MAX];
  MESSAGE *msg = NULL;

  if (!h) {
    /* Try to bounce each message out, aborting if we get any failures. */
    for (i = 0; i < Context->msgcount; i++)
      if (Context->hdrs[i]->tagged)
        ret |=
          _mutt_bounce_message (fp, Context->hdrs[i], to, resent_from,
                                env_from);
    return ret;
  }

  /* If we failed to open a message, return with error */
  if (!fp && (msg = mx_open_message (Context, h->msgno)) == NULL)
    return -1;

  if (!fp)
    fp = msg->fp;

  mutt_mktemp (tempfile);
  if ((f = safe_fopen (tempfile, "w")) != NULL) {
    int ch_flags = CH_XMIT | CH_NONEWLINE | CH_NOQFROM;

    if (!option (OPTBOUNCEDELIVERED))
      ch_flags |= CH_WEED_DELIVERED;

    fseeko (fp, h->offset, 0);
    fprintf (f, "Resent-From: %s", resent_from);
    fprintf (f, "\nResent-%s", mutt_make_date (date, sizeof (date)));
    if (MsgIdFormat && *MsgIdFormat)
      fprintf (f, "Resent-Message-ID: %s\n", mutt_gen_msgid ());
    fputs ("Resent-To: ", f);
    mutt_write_address_list (to, f, 11, 0);
    mutt_copy_header (fp, h, f, ch_flags, NULL);
    fputc ('\n', f);
    mutt_copy_bytes (fp, f, h->content->length);
    fclose (f);

    ret = mutt_invoke_mta (env_from, to, NULL, NULL, tempfile,
                           h->content->encoding == ENC8BIT);
  }

  if (msg)
    mx_close_message (&msg);

  return ret;
}

int mutt_bounce_message (FILE * fp, HEADER * h, address_t * to)
{
  address_t *from;
  const char *fqdn = mutt_fqdn (1);
  char resent_from[STRING];
  int ret;
  char *err;

  resent_from[0] = '\0';
  from = mutt_default_from ();

  if (fqdn)
    rfc822_qualify (from, fqdn);

  rfc2047_encode_adrlist (from, "Resent-From");
  if (mutt_addrlist_to_idna (from, &err)) {
    mutt_error (_("Bad IDN %s while preparing resent-from."), err);
    return -1;
  }
  rfc822_write_address (resent_from, sizeof (resent_from), from, 0);

#ifdef USE_NNTP
  unset_option (OPTNEWSSEND);
#endif

  ret = _mutt_bounce_message (fp, h, to, resent_from, from);

  address_delete (&from);

  return ret;
}


/* given a list of addresses, return a list of unique addresses */
address_t *mutt_remove_duplicates (address_t * addr)
{
  address_t *top = addr;
  address_t **last = &top;
  address_t *tmp;
  int dup;

  while (addr) {
    for (tmp = top, dup = 0; tmp && tmp != addr; tmp = tmp->next) {
      if (tmp->mailbox && addr->mailbox &&
          !ascii_strcasecmp (addr->mailbox, tmp->mailbox)) {
        dup = 1;
        break;
      }
    }

    if (dup) {
      debug_print (2, ("Removing %s\n", addr->mailbox));

      *last = addr->next;

      addr->next = NULL;
      address_delete (&addr);

      addr = *last;
    }
    else {
      last = &addr->next;
      addr = addr->next;
    }
  }

  return (top);
}

static void set_noconv_flags (BODY * b, short flag)
{
  for (; b; b = b->next) {
    if (b->type == TYPEMESSAGE || b->type == TYPEMULTIPART)
      set_noconv_flags (b->parts, flag);
    else if (b->type == TYPETEXT && b->noconv) {
      if (flag)
        mutt_set_parameter ("x-mutt-noconv", "yes", &b->parameter);
      else
        mutt_delete_parameter ("x-mutt-noconv", &b->parameter);
    }
  }
}

int mutt_write_fcc (const char *path, HEADER * hdr, const char *msgid,
                    int post, char *fcc)
{
  CONTEXT f;
  MESSAGE *msg;
  char tempfile[_POSIX_PATH_MAX];
  FILE *tempfp = NULL;
  int r;

  if (post)
    set_noconv_flags (hdr->content, 1);

  if (mx_open_mailbox (path, M_APPEND | M_QUIET, &f) == NULL) {
    debug_print (1, ("unable to open mailbox %s in append-mode, aborting.\n", path));
    return (-1);
  }

  /* We need to add a Content-Length field to avoid problems where a line in
   * the message body begins with "From "   
   */
  if (f.magic == M_MMDF || f.magic == M_MBOX) {
    mutt_mktemp (tempfile);
    if ((tempfp = safe_fopen (tempfile, "w+")) == NULL) {
      mutt_perror (tempfile);
      mx_close_mailbox (&f, NULL);
      return (-1);
    }
  }

  hdr->read = !post;            /* make sure to put it in the `cur' directory (maildir) */
  if ((msg = mx_open_new_message (&f, hdr, M_ADD_FROM)) == NULL) {
    mx_close_mailbox (&f, NULL);
    return (-1);
  }

  /* post == 1 => postpone message. Set mode = -1 in mutt_write_rfc822_header()
   * post == 0 => Normal mode. Set mode = 0 in mutt_write_rfc822_header() 
   * */
  mutt_write_rfc822_header (msg->fp, hdr->env, hdr->content, post ? -post : 0,
                            0);

  /* (postponment) if this was a reply of some sort, <msgid> contians the
   * Message-ID: of message replied to.  Save it using a special X-Mutt-
   * header so it can be picked up if the message is recalled at a later
   * point in time.  This will allow the message to be marked as replied if
   * the same mailbox is still open.
   */
  if (post && msgid)
    fprintf (msg->fp, "X-Mutt-References: %s\n", msgid);

  /* (postponment) save the Fcc: using a special X-Mutt- header so that
   * it can be picked up when the message is recalled 
   */
  if (post && fcc)
    fprintf (msg->fp, "X-Mutt-Fcc: %s\n", fcc);
  fprintf (msg->fp, "Status: RO\n");



  /* (postponment) if the mail is to be signed or encrypted, save this info */
  if (post && (hdr->security & APPLICATION_PGP)) {
    fputs ("X-Mutt-PGP: ", msg->fp);
    if (hdr->security & ENCRYPT)
      fputc ('E', msg->fp);
    if (hdr->security & SIGN) {
      fputc ('S', msg->fp);
      if (PgpSignAs && *PgpSignAs)
        fprintf (msg->fp, "<%s>", PgpSignAs);
    }
    if (hdr->security & INLINE)
      fputc ('I', msg->fp);
    fputc ('\n', msg->fp);
  }

  /* (postponment) if the mail is to be signed or encrypted, save this info */
  if (post && (hdr->security & APPLICATION_SMIME)) {
    fputs ("X-Mutt-SMIME: ", msg->fp);
    if (hdr->security & ENCRYPT) {
      fputc ('E', msg->fp);
      if (SmimeCryptAlg && *SmimeCryptAlg)
        fprintf (msg->fp, "C<%s>", SmimeCryptAlg);
    }
    if (hdr->security & SIGN) {
      fputc ('S', msg->fp);
      if (SmimeDefaultKey && *SmimeDefaultKey)
        fprintf (msg->fp, "<%s>", SmimeDefaultKey);
    }
    if (hdr->security & INLINE)
      fputc ('I', msg->fp);
    fputc ('\n', msg->fp);
  }

#ifdef MIXMASTER
  /* (postponement) if the mail is to be sent through a mixmaster 
   * chain, save that information
   */

  if (post && hdr->chain && hdr->chain) {
    LIST *p;

    fputs ("X-Mutt-Mix:", msg->fp);
    for (p = hdr->chain; p; p = p->next)
      fprintf (msg->fp, " %s", (char *) p->data);

    fputc ('\n', msg->fp);
  }
#endif

  if (tempfp) {
    char sasha[LONG_STRING];
    int lines = 0;

    mutt_write_mime_body (hdr->content, tempfp);

    /* make sure the last line ends with a newline.  Emacs doesn't ensure
     * this will happen, and it can cause problems parsing the mailbox   
     * later.
     */
    fseeko (tempfp, -1, 2);
    if (fgetc (tempfp) != '\n') {
      fseeko (tempfp, 0, 2);
      fputc ('\n', tempfp);
    }

    fflush (tempfp);
    if (ferror (tempfp)) {
      debug_print (1, ("%s: write failed.\n", tempfile));
      fclose (tempfp);
      unlink (tempfile);
      mx_commit_message (msg, &f);      /* XXX - really? */
      mx_close_message (&msg);
      mx_close_mailbox (&f, NULL);
      return -1;
    }

    /* count the number of lines */
    rewind (tempfp);
    while (fgets (sasha, sizeof (sasha), tempfp) != NULL)
      lines++;
    fprintf (msg->fp, "Content-Length: %zd\n", ftello (tempfp));
    fprintf (msg->fp, "Lines: %d\n\n", lines);

    /* copy the body and clean up */
    rewind (tempfp);
    r = mutt_copy_stream (tempfp, msg->fp);
    if (fclose (tempfp) != 0)
      r = -1;
    /* if there was an error, leave the temp version */
    if (!r)
      unlink (tempfile);
  }
  else {
    fputc ('\n', msg->fp);      /* finish off the header */
    r = mutt_write_mime_body (hdr->content, msg->fp);
  }

  if (mx_commit_message (msg, &f) != 0)
    r = -1;
  mx_close_message (&msg);
  mx_close_mailbox (&f, NULL);

  if (post)
    set_noconv_flags (hdr->content, 0);

  return r;
}