copy.c

/*
 * Copyright (C) 1996-2000,2002,2014 Michael R. Elkins <me@mutt.org>
 *
 *     This program is free software; you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation; either version 2 of the License, or
 *     (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program; if not, write to the Free Software
 *     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

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

#include "mutt.h"
#include "mailbox.h"
#include "mx.h"
#include "copy.h"
#include "rfc2047.h"
#include "mime.h"
#include "mutt_crypt.h"
#include "mutt_idna.h"
#include "mutt_curses.h"

#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h> /* needed for SEEK_SET under SunOS 4.1.4 */

static int address_header_decode (char **str);
static int copy_delete_attach (BODY *b, FILE *fpin, FILE *fpout, const char *date);

/* Ok, the only reason for not merging this with mutt_copy_header()
 * below is to avoid creating a HEADER structure in message_handler().
 * Also, this one will wrap headers much more aggressively than the other one.
 */
int
mutt_copy_hdr (FILE *in, FILE *out, LOFF_T off_start, LOFF_T off_end, int flags,
	       const char *prefix)
{
  int from = 0;
  int this_is_from;
  int ignore = 0;
  char buf[LONG_STRING]; /* should be long enough to get most fields in one pass */
  char *nl;
  LIST *t;
  char **headers;
  int hdr_count;
  int x;
  char *this_one = NULL;
  size_t this_one_len = 0;
  int error;

  if (ftello (in) != off_start)
    fseeko (in, off_start, SEEK_SET);

  buf[0] = '\n';
  buf[1] = 0;

  if ((flags & (CH_REORDER | CH_WEED | CH_MIME | CH_DECODE | CH_PREFIX | CH_WEED_DELIVERED)) == 0)
  {
    /* Without these flags to complicate things
     * we can do a more efficient line to line copying
     */
    while (ftello (in) < off_end)
    {
      nl = strchr (buf, '\n');

      if ((fgets (buf, sizeof (buf), in)) == NULL)
	break;

      /* Is it the beginning of a header? */
      if (nl && buf[0] != ' ' && buf[0] != '\t')
      {
	ignore = 1;
	if (!from && mutt_strncmp ("From ", buf, 5) == 0)
	{
	  if ((flags & CH_FROM) == 0)
	    continue;
	  from = 1;
	}
	else if (flags & (CH_NOQFROM) &&
                 ascii_strncasecmp (">From ", buf, 6) == 0)
          continue;

	else if (buf[0] == '\n' || (buf[0] == '\r' && buf[1] == '\n'))
	  break; /* end of header */

	if ((flags & (CH_UPDATE | CH_XMIT | CH_NOSTATUS)) &&
	    (ascii_strncasecmp ("Status:", buf, 7) == 0 ||
	     ascii_strncasecmp ("X-Status:", buf, 9) == 0))
	  continue;
	if ((flags & (CH_UPDATE_LEN | CH_XMIT | CH_NOLEN)) &&
	    (ascii_strncasecmp ("Content-Length:", buf, 15) == 0 ||
	     ascii_strncasecmp ("Lines:", buf, 6) == 0))
	  continue;
	if ((flags & CH_UPDATE_REFS) &&
	    ascii_strncasecmp ("References:", buf, 11) == 0)
	  continue;
	if ((flags & CH_UPDATE_IRT) &&
	    ascii_strncasecmp ("In-Reply-To:", buf, 12) == 0)
	  continue;
        if ((flags & CH_UPDATE_LABEL) &&
            ascii_strncasecmp ("X-Label:", buf, 8) == 0)
          continue;
        if ((flags & CH_UPDATE_SUBJECT) &&
            ascii_strncasecmp ("Subject:", buf, 8) == 0)
          continue;

	ignore = 0;
      }

      if (!ignore && fputs (buf, out) == EOF)
	return (-1);
    }
    return 0;
  }

  hdr_count = 1;
  x = 0;
  error = FALSE;

  /* We are going to read and collect the headers in an array
   * so we are able to do re-ordering.
   * First count the number of entries in the array
   */
  if (flags & CH_REORDER)
  {
    for (t = HeaderOrderList; t; t = t->next)
    {
      dprint(3, (debugfile, "Reorder list: %s\n", t->data));
      hdr_count++;
    }
  }

  dprint (1, (debugfile, "WEED is %s\n", (flags & CH_WEED) ? "Set" : "Not Set"));

  headers = safe_calloc (hdr_count, sizeof (char *));

  /* Read all the headers into the array */
  while (ftello (in) < off_end)
  {
    nl = strchr (buf, '\n');

    /* Read a line */
    if ((fgets (buf, sizeof (buf), in)) == NULL)
      break;

    /* Is it the beginning of a header? */
    if (nl && buf[0] != ' ' && buf[0] != '\t')
    {
      /* Do we have anything pending? */
      if (this_one)
      {
	if (flags & CH_DECODE)
	{
	  if (!address_header_decode (&this_one))
	    rfc2047_decode (&this_one);
	  this_one_len = mutt_strlen (this_one);
	}

	if (!headers[x])
	  headers[x] = this_one;
	else
	{
	  size_t hlen = mutt_strlen (headers[x]);

	  safe_realloc (&headers[x], hlen + this_one_len + sizeof (char));
	  strcat (headers[x] + hlen, this_one); /* __STRCAT_CHECKED__ */
	  FREE (&this_one);
	}

	this_one = NULL;
      }

      ignore = 1;
      this_is_from = 0;
      if (!from && mutt_strncmp ("From ", buf, 5) == 0)
      {
	if ((flags & CH_FROM) == 0)
	  continue;
	this_is_from = from = 1;
      }
      else if (buf[0] == '\n' || (buf[0] == '\r' && buf[1] == '\n'))
	break; /* end of header */

      /* note: CH_FROM takes precedence over header weeding. */
      if (!((flags & CH_FROM) && (flags & CH_FORCE_FROM) && this_is_from) &&
	  (flags & CH_WEED) &&
	  mutt_matches_ignore (buf, Ignore) &&
	  !mutt_matches_ignore (buf, UnIgnore))
	continue;
      if ((flags & CH_WEED_DELIVERED) &&
	  ascii_strncasecmp ("Delivered-To:", buf, 13) == 0)
	continue;
      if ((flags & (CH_UPDATE | CH_XMIT | CH_NOSTATUS)) &&
	  (ascii_strncasecmp ("Status:", buf, 7) == 0 ||
	   ascii_strncasecmp ("X-Status:", buf, 9) == 0))
	continue;
      if ((flags & (CH_UPDATE_LEN | CH_XMIT | CH_NOLEN)) &&
	  (ascii_strncasecmp ("Content-Length:", buf, 15) == 0 ||
	   ascii_strncasecmp ("Lines:", buf, 6) == 0))
	continue;
      if ((flags & CH_MIME) &&
	  ((ascii_strncasecmp ("content-", buf, 8) == 0 &&
	    (ascii_strncasecmp ("transfer-encoding:", buf + 8, 18) == 0 ||
	     ascii_strncasecmp ("type:", buf + 8, 5) == 0)) ||
	   ascii_strncasecmp ("mime-version:", buf, 13) == 0))
	continue;
      if ((flags & CH_UPDATE_REFS) &&
	  ascii_strncasecmp ("References:", buf, 11) == 0)
	continue;
      if ((flags & CH_UPDATE_IRT) &&
	  ascii_strncasecmp ("In-Reply-To:", buf, 12) == 0)
	continue;
      if ((flags & CH_UPDATE_LABEL) &&
          ascii_strncasecmp ("X-Label:", buf, 8) == 0)
        continue;
      if ((flags & CH_UPDATE_SUBJECT) &&
          ascii_strncasecmp ("Subject:", buf, 8) == 0)
        continue;

      /* Find x -- the array entry where this header is to be saved */
      if (flags & CH_REORDER)
      {
        int match = -1;
        size_t match_len = 0, hdr_order_len;

	for (t = HeaderOrderList, x = 0 ; (t) ; t = t->next, x++)
	{
          hdr_order_len = mutt_strlen (t->data);
	  if (!ascii_strncasecmp (buf, t->data, hdr_order_len))
	  {
            if ((match == -1) || (hdr_order_len > match_len))
            {
              match = x;
              match_len = hdr_order_len;
            }
	    dprint(2, (debugfile, "Reorder: %s matches %s\n", t->data, buf));
	  }
	}
        if (match != -1)
          x = match;
      }

      ignore = 0;
    } /* If beginning of header */

    if (!ignore)
    {
      dprint (2, (debugfile, "Reorder: x = %d; hdr_count = %d\n", x, hdr_count));
      if (!this_one)
      {
	this_one = safe_strdup (buf);
	this_one_len = mutt_strlen (this_one);
      }
      else
      {
	size_t blen = mutt_strlen (buf);

	safe_realloc (&this_one, this_one_len + blen + sizeof (char));
	strcat (this_one + this_one_len, buf); /* __STRCAT_CHECKED__ */
	this_one_len += blen;
      }
    }
  } /* while (ftello (in) < off_end) */

  /* Do we have anything pending?  -- XXX, same code as in above in the loop. */
  if (this_one)
  {
    if (flags & CH_DECODE)
    {
      if (!address_header_decode (&this_one))
	rfc2047_decode (&this_one);
      this_one_len = mutt_strlen (this_one);
    }

    if (!headers[x])
      headers[x] = this_one;
    else
    {
      size_t hlen = mutt_strlen (headers[x]);

      safe_realloc (&headers[x], hlen + this_one_len + sizeof (char));
      strcat (headers[x] + hlen, this_one); /* __STRCAT_CHECKED__ */
      FREE (&this_one);
    }

    this_one = NULL;
  }

  /* Now output the headers in order */
  for (x = 0; x < hdr_count; x++)
  {
    if (headers[x])
    {
      /* We couldn't do the prefixing when reading because RFC 2047
       * decoding may have concatenated lines.
       */

      if (flags & (CH_DECODE|CH_PREFIX))
      {
	if (mutt_write_one_header (out, 0, headers[x],
				   flags & CH_PREFIX ? prefix : 0,
                                   mutt_window_wrap_cols (MuttIndexWindow, Wrap), flags) == -1)
	{
	  error = TRUE;
	  break;
	}
      }
      else
      {
	if (fputs (headers[x], out) == EOF)
	{
	  error = TRUE;
	  break;
	}
      }
    }
  }

  /* Free in a separate loop to be sure that all headers are freed
   * in case of error. */
  for (x = 0; x < hdr_count; x++)
    FREE (&headers[x]);
  FREE (&headers);

  if (error)
    return (-1);
  return (0);
}

/* flags:
   CH_DECODE            RFC2047 header decoding
   CH_FROM              retain the "From " message separator
   CH_FORCE_FROM        give CH_FROM precedence over CH_WEED
   CH_MIME              ignore MIME fields
   CH_NOLEN             don't write Content-Length: and Lines:
   CH_NONEWLINE         don't output a newline after the header
   CH_NOSTATUS          ignore the Status: and X-Status:
   CH_PREFIX            quote header with $indent_str
   CH_REORDER           output header in order specified by `hdr_order'
   CH_TXTPLAIN          generate text/plain MIME headers [hack alert.]
   CH_UPDATE            write new Status: and X-Status:
   CH_UPDATE_LEN        write new Content-Length: and Lines:
   CH_XMIT              ignore Lines: and Content-Length:
   CH_WEED              do header weeding
   CH_NOQFROM           ignore ">From " line
   CH_UPDATE_IRT        update the In-Reply-To: header
   CH_UPDATE_REFS       update the References: header
   CH_UPDATE_LABEL      update the X-Label: header

   prefix:
   string to use if CH_PREFIX is set
*/

int
mutt_copy_header (FILE *in, HEADER *h, FILE *out, int flags, const char *prefix)
{
  char buffer[SHORT_STRING];
  char *temp_hdr = NULL;

  if (h->env)
    flags |= ((h->env->changed & MUTT_ENV_CHANGED_IRT) ? CH_UPDATE_IRT : 0)
      | ((h->env->changed & MUTT_ENV_CHANGED_REFS) ? CH_UPDATE_REFS : 0)
      | ((h->env->changed & MUTT_ENV_CHANGED_XLABEL) ? CH_UPDATE_LABEL : 0)
      | ((h->env->changed & MUTT_ENV_CHANGED_SUBJECT) ? CH_UPDATE_SUBJECT : 0);

  if (mutt_copy_hdr (in, out, h->offset, h->content->offset, flags, prefix) == -1)
    return -1;

  if (flags & CH_TXTPLAIN)
  {
    char chsbuf[SHORT_STRING];
    fputs ("MIME-Version: 1.0\n", out);
    fputs ("Content-Transfer-Encoding: 8bit\n", out);
    fputs ("Content-Type: text/plain; charset=", out);
    mutt_canonical_charset (chsbuf, sizeof (chsbuf), Charset ? Charset : "us-ascii");
    rfc822_cat(buffer, sizeof(buffer), chsbuf, MimeSpecials);
    fputs(buffer, out);
    fputc('\n', out);
  }

  if ((flags & CH_UPDATE_IRT) && h->env->in_reply_to)
  {
    LIST *listp = h->env->in_reply_to;
    fputs ("In-Reply-To:", out);
    for (; listp; listp = listp->next)
    {
      fputc (' ', out);
      fputs (listp->data, out);
    }
    fputc ('\n', out);
  }

  if ((flags & CH_UPDATE_REFS) && h->env->references)
  {
    fputs ("References:", out);
    mutt_write_references (h->env->references, out, 0);
    fputc ('\n', out);
  }

  if ((flags & CH_UPDATE) && (flags & CH_NOSTATUS) == 0)
  {
    if (h->old || h->read)
    {
      fputs ("Status: ", out);
      if (h->read)
	fputs ("RO", out);
      else if (h->old)
	fputc ('O', out);
      fputc ('\n', out);
    }

    if (h->flagged || h->replied)
    {
      fputs ("X-Status: ", out);
      if (h->replied)
	fputc ('A', out);
      if (h->flagged)
	fputc ('F', out);
      fputc ('\n', out);
    }
  }

  if (flags & CH_UPDATE_LEN &&
      (flags & CH_NOLEN) == 0)
  {
    fprintf (out, "Content-Length: " OFF_T_FMT "\n", h->content->length);
    if (h->lines != 0 || h->content->length == 0)
      fprintf (out, "Lines: %d\n", h->lines);
  }

  if ((flags & CH_UPDATE_LABEL) && h->env->x_label)
  {
    temp_hdr = h->env->x_label;
    /* env->x_label isn't currently stored with direct references
     * elsewhere.  Context->label_hash strdups the keys.  But to be
     * safe, encode a copy */
    if (!(flags & CH_DECODE))
    {
      temp_hdr = safe_strdup (temp_hdr);
      rfc2047_encode_string (&temp_hdr);
    }
    if (mutt_write_one_header (out, "X-Label", temp_hdr,
                               flags & CH_PREFIX ? prefix : 0,
                               mutt_window_wrap_cols (MuttIndexWindow, Wrap),
                               flags) == -1)
      return -1;
    if (!(flags & CH_DECODE))
      FREE (&temp_hdr);
  }

  if ((flags & CH_UPDATE_SUBJECT) && h->env->subject)
  {
    temp_hdr = h->env->subject;
    /* env->subject is directly referenced in Context->subj_hash, so we
     * have to be careful not to encode (and thus free) that memory. */
    if (!(flags & CH_DECODE))
    {
      temp_hdr = safe_strdup (temp_hdr);
      rfc2047_encode_string (&temp_hdr);
    }
    if (mutt_write_one_header (out, "Subject", temp_hdr,
                               flags & CH_PREFIX ? prefix : 0,
                               mutt_window_wrap_cols (MuttIndexWindow, Wrap),
                               flags) == -1)
      return -1;
    if (!(flags & CH_DECODE))
      FREE (&temp_hdr);
  }

  if ((flags & CH_NONEWLINE) == 0)
  {
    if (flags & CH_PREFIX)
      fputs(prefix, out);
    fputc ('\n', out); /* add header terminator */
  }

  if (ferror (out) || feof (out))
    return -1;

  return 0;
}

/* Count the number of lines and bytes to be deleted in this body*/
static int count_delete_lines (FILE *fp, BODY *b, LOFF_T *length, size_t datelen)
{
  int dellines = 0;
  LOFF_T l;
  int ch;

  if (b->deleted)
  {
    fseeko (fp, b->offset, SEEK_SET);
    for (l = b->length ; l ; l --)
    {
      ch = getc (fp);
      if (ch == EOF)
	break;
      if (ch == '\n')
	dellines ++;
    }
    /* 3 and 89 come from the added header of three lines in
     * copy_delete_attach().  89 is the size of the header (including
     * the newlines, tabs, and a single digit length), not including
     * the date length. */
    dellines -= 3;
    *length -= b->length - (89 + datelen);
    /* Count the number of digits exceeding the first one to write the size */
    for (l = 10 ; b->length >= l ; l *= 10)
      (*length) ++;
  }
  else
  {
    for (b = b->parts ; b ; b = b->next)
      dellines += count_delete_lines (fp, b, length, datelen);
  }
  return dellines;
}

/* make a copy of a message
 *
 * fpout	where to write output
 * fpin		where to get input
 * hdr		header of message being copied
 * body		structure of message being copied
 * flags
 * 	MUTT_CM_NOHEADER	don't copy header
 * 	MUTT_CM_PREFIX	quote header and body
 *	MUTT_CM_DECODE	decode message body to text/plain
 *	MUTT_CM_DISPLAY	displaying output to the user
 *      MUTT_CM_PRINTING   printing the message
 *	MUTT_CM_UPDATE	update structures in memory after syncing
 *	MUTT_CM_DECODE_PGP	used for decoding PGP messages
 *	MUTT_CM_CHARCONV	perform character set conversion
 * chflags	flags to mutt_copy_header()
 */

int
_mutt_copy_message (FILE *fpout, FILE *fpin, HEADER *hdr, BODY *body,
		    int flags, int chflags)
{
  char prefix[SHORT_STRING];
  STATE s;
  LOFF_T new_offset = -1;
  int rc = 0;

  if (flags & MUTT_CM_PREFIX)
  {
    if (option (OPTTEXTFLOWED))
      strfcpy (prefix, ">", sizeof (prefix));
    else
      _mutt_make_string (prefix, sizeof (prefix), NONULL (Prefix), Context, hdr, 0);
  }

  if ((flags & MUTT_CM_NOHEADER) == 0)
  {
    if (flags & MUTT_CM_PREFIX)
      chflags |= CH_PREFIX;

    else if (hdr->attach_del && (chflags & CH_UPDATE_LEN))
    {
      int new_lines, attach_del_rc = -1;
      LOFF_T new_length = body->length;
      BUFFER *quoted_date = NULL;

      quoted_date = mutt_buffer_pool_get ();
      mutt_buffer_addch (quoted_date, '"');
      mutt_make_date (quoted_date);
      mutt_buffer_addch (quoted_date, '"');

      /* Count the number of lines and bytes to be deleted */
      fseeko (fpin, body->offset, SEEK_SET);
      new_lines = hdr->lines -
	count_delete_lines (fpin, body, &new_length, mutt_buffer_len (quoted_date));

      /* Copy the headers */
      if (mutt_copy_header (fpin, hdr, fpout,
			    chflags | CH_NOLEN | CH_NONEWLINE, NULL))
	goto attach_del_cleanup;
      fprintf (fpout, "Content-Length: " OFF_T_FMT "\n", new_length);
      if (new_lines <= 0)
	new_lines = 0;
      else
	fprintf (fpout, "Lines: %d\n", new_lines);

      putc ('\n', fpout);
      if (ferror (fpout) || feof (fpout))
	goto attach_del_cleanup;
      new_offset = ftello (fpout);

      /* Copy the body */
      fseeko (fpin, body->offset, SEEK_SET);
      if (copy_delete_attach (body, fpin, fpout, mutt_b2s (quoted_date)))
	goto attach_del_cleanup;

      mutt_buffer_pool_release (&quoted_date);

#ifdef DEBUG
      {
	LOFF_T fail = ((ftello (fpout) - new_offset) - new_length);

	if (fail)
	{
	  mutt_error ("The length calculation was wrong by %ld bytes", fail);
	  new_length += fail;
	  mutt_sleep (1);
	}
      }
#endif

      /* Update original message if we are sync'ing a mailfolder */
      if (flags & MUTT_CM_UPDATE)
      {
	hdr->attach_del = 0;
	hdr->lines = new_lines;
	body->offset = new_offset;

	/* update the total size of the mailbox to reflect this deletion */
	Context->size -= body->length - new_length;
	/*
	 * if the message is visible, update the visible size of the mailbox
	 * as well.
	 */
	if (Context->v2r[hdr->msgno] != -1)
	  Context->vsize -= body->length - new_length;

	body->length = new_length;
	mutt_free_body (&body->parts);
      }

      attach_del_rc = 0;

    attach_del_cleanup:
      mutt_buffer_pool_release (&quoted_date);
      return attach_del_rc;
    }

    if (mutt_copy_header (fpin, hdr, fpout, chflags,
			  (chflags & CH_PREFIX) ? prefix : NULL) == -1)
      return -1;

    new_offset = ftello (fpout);
  }

  if (flags & MUTT_CM_DECODE)
  {
    /* now make a text/plain version of the message */
    memset (&s, 0, sizeof (STATE));
    s.fpin = fpin;
    s.fpout = fpout;
    if (flags & MUTT_CM_PREFIX)
      s.prefix = prefix;
    if (flags & MUTT_CM_DISPLAY)
      s.flags |= MUTT_DISPLAY;
    if (flags & MUTT_CM_PRINTING)
      s.flags |= MUTT_PRINTING;
    if (flags & MUTT_CM_WEED)
      s.flags |= MUTT_WEED;
    if (flags & MUTT_CM_CHARCONV)
      s.flags |= MUTT_CHARCONV;
    if (flags & MUTT_CM_REPLYING)
      s.flags |= MUTT_REPLYING;
    if (flags & MUTT_CM_FORWARDING)
      s.flags |= MUTT_FORWARDING;

    if (WithCrypto && flags & MUTT_CM_VERIFY)
      s.flags |= MUTT_VERIFY;

    rc = mutt_body_handler (body, &s);
  }
  else if (WithCrypto
           && (flags & MUTT_CM_DECODE_CRYPT) && (hdr->security & ENCRYPT))
  {
    BODY *cur = NULL;
    FILE *fp;

    if ((WithCrypto & APPLICATION_PGP)
        && (flags & MUTT_CM_DECODE_PGP) && (hdr->security & APPLICATION_PGP) &&
	hdr->content->type == TYPEMULTIPART)
    {
      if (crypt_pgp_decrypt_mime (fpin, &fp, hdr->content, &cur))
	return (-1);
      fputs ("MIME-Version: 1.0\n", fpout);
    }

    if ((WithCrypto & APPLICATION_SMIME)
        && (flags & MUTT_CM_DECODE_SMIME) && (hdr->security & APPLICATION_SMIME)
        && hdr->content->type == TYPEAPPLICATION)
    {
      if (crypt_smime_decrypt_mime (fpin, &fp, hdr->content, &cur))
	return (-1);
    }

    if (!cur)
    {
      mutt_error (_("No decryption engine available for message"));
      return -1;
    }

    mutt_write_mime_header (cur, fpout);
    fputc ('\n', fpout);

    fseeko (fp, cur->offset, SEEK_SET);
    if (mutt_copy_bytes (fp, fpout, cur->length) == -1)
    {
      safe_fclose (&fp);
      mutt_free_body (&cur);
      return (-1);
    }
    mutt_free_body (&cur);
    safe_fclose (&fp);
  }
  else
  {
    fseeko (fpin, body->offset, SEEK_SET);
    if (flags & MUTT_CM_PREFIX)
    {
      int c;
      size_t bytes = body->length;

      fputs(prefix, fpout);

      while ((c = fgetc(fpin)) != EOF && bytes--)
      {
	fputc(c, fpout);
	if (c == '\n')
	{
	  fputs(prefix, fpout);
	}
      }
    }
    else if (mutt_copy_bytes (fpin, fpout, body->length) == -1)
      return -1;
  }

  if ((flags & MUTT_CM_UPDATE) && (flags & MUTT_CM_NOHEADER) == 0
      && new_offset != -1)
  {
    body->offset = new_offset;
    mutt_free_body (&body->parts);
  }

  return rc;
}

/* Returns:
 *    0 on success
 *   -1 on a fatal error
 *    1 on a partial decode, or errors that are still deemed viewable
 *      by mutt_display_message() (such as decryption errors).
 * Callers besides mutt_display_message should consider rc != 0 as
 * failure.
 */
int
mutt_copy_message (FILE *fpout, CONTEXT *src, HEADER *hdr, int flags,
		   int chflags)
{
  MESSAGE *msg;
  int r;

  if ((msg = mx_open_message (src, hdr->msgno, 0)) == NULL)
    return -1;
  r = _mutt_copy_message (fpout, msg->fp, hdr, hdr->content, flags, chflags);
  if ((r >= 0) && (ferror (fpout) || feof (fpout)))
  {
    dprint (1, (debugfile, "_mutt_copy_message failed to detect EOF!\n"));
    r = -1;
  }
  mx_close_message (src, &msg);
  return r;
}

/* appends a copy of the given message to a mailbox
 *
 * dest		destination mailbox
 * fpin		where to get input
 * src		source mailbox
 * hdr		message being copied
 * body		structure of message being copied
 * flags	mutt_copy_message() flags
 * chflags	mutt_copy_header() flags
 */

int
_mutt_append_message (CONTEXT *dest, FILE *fpin, CONTEXT *src, HEADER *hdr,
		      BODY *body, int flags, int chflags)
{
  char buf[STRING];
  MESSAGE *msg;
  int r;

  fseeko (fpin, hdr->offset, SEEK_SET);
  if (fgets (buf, sizeof (buf), fpin) == NULL)
    return -1;

  if ((msg = mx_open_new_message (dest, hdr, is_from (buf, NULL, 0, NULL) ? 0 : MUTT_ADD_FROM)) == NULL)
    return -1;
  if (dest->magic == MUTT_MBOX || dest->magic == MUTT_MMDF)
    chflags |= CH_FROM | CH_FORCE_FROM;
  chflags |= (dest->magic == MUTT_MAILDIR ? CH_NOSTATUS : CH_UPDATE);
  r = _mutt_copy_message (msg->fp, fpin, hdr, body, flags, chflags);
  /* Partial decode is still an error. */
  if (r != 0)
    r = -1;
  if (mx_commit_message (msg, dest) != 0)
    r = -1;

  mx_close_message (dest, &msg);
  return r;
}

int
mutt_append_message (CONTEXT *dest, CONTEXT *src, HEADER *hdr, int cmflags,
		     int chflags)
{
  MESSAGE *msg;
  int r;

  if ((msg = mx_open_message (src, hdr->msgno, 0)) == NULL)
    return -1;
  r = _mutt_append_message (dest, msg->fp, src, hdr, hdr->content, cmflags, chflags);
  mx_close_message (src, &msg);
  return r;
}

/*
 * This function copies a message body, while deleting _in_the_copy_
 * any attachments which are marked for deletion.
 * Nothing is changed in the original message -- this is left to the caller.
 *
 * The function will return 0 on success and -1 on failure.
 */
static int copy_delete_attach (BODY *b, FILE *fpin, FILE *fpout,
                               const char *quoted_date)
{
  BODY *part;

  for (part = b->parts ; part ; part = part->next)
  {
    if (part->deleted || part->parts)
    {
      /* Copy till start of this part */
      if (mutt_copy_bytes (fpin, fpout, part->hdr_offset - ftello (fpin)))
	return -1;

      if (part->deleted)
      {
        /* If this is modified, count_delete_lines() needs to be changed too */
	fprintf (fpout,
		 "Content-Type: message/external-body; access-type=x-mutt-deleted;\n"
		 "\texpiration=%s; length=" OFF_T_FMT "\n"
		 "\n", quoted_date, part->length);
	if (ferror (fpout))
	  return -1;

	/* Copy the original mime headers */
	if (mutt_copy_bytes (fpin, fpout, part->offset - ftello (fpin)))
	  return -1;

	/* Skip the deleted body */
	fseeko (fpin, part->offset + part->length, SEEK_SET);
      }
      else
      {
	if (copy_delete_attach (part, fpin, fpout, quoted_date))
	  return -1;
      }
    }
  }

  /* Copy the last parts */
  if (mutt_copy_bytes (fpin, fpout, b->offset + b->length - ftello (fpin)))
    return -1;

  return 0;
}

/*
 * This function is the equivalent of mutt_write_address_list(),
 * but writes to a buffer instead of writing to a stream.
 * mutt_write_address_list could be re-used if we wouldn't store
 * all the decoded headers in a huge array, first.
 *
 * XXX - fix that.
 */

static void format_address_header (char **h, ADDRESS *a)
{
  ADDRESS *prev;
  char buf[HUGE_STRING];
  char cbuf[STRING];
  char c2buf[STRING];
  char *p = NULL;
  int l, linelen, buflen, count, cbuflen, c2buflen, plen;

  linelen = mutt_strlen (*h);
  plen = linelen;
  buflen  = linelen + 3;

  safe_realloc (h, buflen);
  for (count = 0; a; a = a->next, count++)
  {
    ADDRESS *tmp = a->next;
    a->next = NULL;
    *buf = *cbuf = *c2buf = '\0';
    l = rfc822_write_address (buf, sizeof (buf), a, 0);
    a->next = tmp;

    if (count && linelen + l > 74)
    {
      strcpy (cbuf, "\n\t");  	/* __STRCPY_CHECKED__ */
      linelen = l + 8;
    }
    else
    {
      /* NOTE: this logic is slightly different from
       * mutt_write_address_list() because the h function parameter
       * starts off without a trailing space.  e.g. "To:".  So this
       * function prepends a space with the *first* address.
       */
      if (a->mailbox && (!count || !prev->group))
      {
	strcpy (cbuf, " ");	/* __STRCPY_CHECKED__ */
	linelen++;
      }
      linelen += l;
    }
    if (!a->group && a->next && a->next->mailbox)
    {
      linelen++;
      buflen++;
      strcpy (c2buf, ",");	/* __STRCPY_CHECKED__ */
    }

    prev = a;

    cbuflen = mutt_strlen (cbuf);
    c2buflen = mutt_strlen (c2buf);
    buflen += l + cbuflen + c2buflen;
    safe_realloc (h, buflen);
    p = *h;
    strcat (p + plen, cbuf);		/* __STRCAT_CHECKED__ */
    plen += cbuflen;
    strcat (p + plen, buf);		/* __STRCAT_CHECKED__ */
    plen += l;
    strcat (p + plen, c2buf);		/* __STRCAT_CHECKED__ */
    plen += c2buflen;
  }

  /* Space for this was allocated in the beginning of this function. */
  strcat (p + plen, "\n");		/* __STRCAT_CHECKED__ */
}

static int address_header_decode (char **h)
{
  char *s = *h;
  int l, rp = 0;

  ADDRESS *a = NULL;
  ADDRESS *cur = NULL;

  switch (tolower ((unsigned char) *s))
  {
    case 'r':
    {
      if (ascii_strncasecmp (s, "return-path:", 12) == 0)
      {
	l = 12;
	rp = 1;
	break;
      }
      else if (ascii_strncasecmp (s, "reply-to:", 9) == 0)
      {
	l = 9;
	break;
      }
      return 0;
    }
    case 'f':
    {
      if (ascii_strncasecmp (s, "from:", 5))
	return 0;
      l = 5;
      break;
    }
    case 'c':
    {
      if (ascii_strncasecmp (s, "cc:", 3))
	return 0;
      l = 3;
      break;

    }
    case 'b':
    {
      if (ascii_strncasecmp (s, "bcc:", 4))
	return 0;
      l = 4;
      break;
    }
    case 's':
    {
      if (ascii_strncasecmp (s, "sender:", 7))
	return 0;
      l = 7;
      break;
    }
    case 't':
    {
      if (ascii_strncasecmp (s, "to:", 3))
	return 0;
      l = 3;
      break;
    }
    case 'm':
    {
      if (ascii_strncasecmp (s, "mail-followup-to:", 17))
	return 0;
      l = 17;
      break;
    }
    default: return 0;
  }

  if ((a = rfc822_parse_adrlist (a, s + l)) == NULL)
    return 0;

  mutt_addrlist_to_local (a);
  rfc2047_decode_adrlist (a);
  for (cur = a; cur; cur = cur->next)
    if (cur->personal)
      rfc822_dequote_comment (cur->personal);

  /* angle brackets for return path are mandated by RfC5322,
   * so leave Return-Path as-is */
  if (rp)
    *h = safe_strdup (s);
  else
  {
    *h = safe_calloc (1, l + 2);
    strfcpy (*h, s, l + 1);
    format_address_header (h, a);
  }

  rfc822_free_address (&a);

  FREE (&s);
  return 1;
}