In compose-mode, removing In-Reply-To: starts thread (Doug McIlroy)..

[s-mailx.git] / collect.c

/*@ S-nail - a mail user agent derived from Berkeley Mail.
 *@ Collect input from standard input, handling ~ escapes.
 *@ TODO This needs a complete rewrite, with carriers, etc.
 *
 * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
 * Copyright (c) 2012 - 2018 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
 */
/*
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#undef n_FILE
#define n_FILE collect

#ifndef HAVE_AMALGAMATION
# include "nail.h"
#endif

struct a_coll_ocs_arg{
   sighandler_type coa_opipe;
   sighandler_type coa_oint;
   FILE *coa_stdin;  /* The descriptor (pipe(2)+Fdopen()) we read from */
   FILE *coa_stdout; /* The Popen()ed pipe through which we write to the hook */
   int coa_pipe[2];  /* ..backing .coa_stdin */
   si8_t *coa_senderr; /* Set to 1 on failure */
   char coa_cmd[n_VFIELD_SIZE(0)];
};

/* The following hookiness with global variables is so that on receipt of an
 * interrupt signal, the partial message can be salted away on *DEAD* */

static sighandler_type  _coll_saveint;    /* Previous SIGINT value */
static sighandler_type  _coll_savehup;    /* Previous SIGHUP value */
static FILE             *_coll_fp;        /* File for saving away */
static int volatile     _coll_hadintr;    /* Have seen one SIGINT so far */
static sigjmp_buf       _coll_jmp;        /* To get back to work */
static sigjmp_buf       _coll_abort;      /* To end collection with error */
static char const *a_coll_ocs__macname;   /* *on-compose-splice* */

/* Handle `~:', `~_' and some hooks; hp may be NULL */
static void       _execute_command(struct header *hp, char const *linebuf,
                     size_t linesize);

/* Return errno */
static si32_t a_coll_include_file(char const *name, bool_t indent,
               bool_t writestat);

/* Execute cmd and insert its standard output into fp, return errno */
static si32_t a_coll_insert_cmd(FILE *fp, char const *cmd);

/* ~p command */
static void       print_collf(FILE *collf, struct header *hp);

/* Write a file, ex-like if f set */
static si32_t a_coll_write(char const *name, FILE *fp, int f);

/* *message-inject-head* */
static bool_t a_coll_message_inject_head(FILE *fp);

/* Parse off the message header from fp and store relevant fields in hp,
 * replace _coll_fp with a shiny new version without any header */
static bool_t a_coll_makeheader(FILE *fp, struct header *hp,
               si8_t *checkaddr_err, bool_t do_delayed_due_t);

/* Edit the message being collected on fp.  On return, make the edit file the
 * new temp file.  Return errno */
static si32_t a_coll_edit(int c, struct header *hp);

/* Pipe the message through the command.  Old message is on stdin of command,
 * new message collected from stdout.  Shell must return 0 to accept new msg */
static si32_t a_coll_pipe(char const *cmd);

/* Interpolate the named messages into the current message, possibly doing
 * indent stuff.  The flag argument is one of the command escapes: [mMfFuU].
 * Return errno */
static si32_t a_coll_forward(char const *ms, FILE *fp, int f);

/* ~^ mode */
static bool_t a_collect_plumbing(char const *ms, struct header *p);

static bool_t a_collect__plumb_header(char const *cp, struct header *p,
               char const *cmd[4]);
static bool_t a_collect__plumb_attach(char const *cp, struct header *p,
               char const *cmd[4]);

/* On interrupt, come here to save the partial message in ~/dead.letter.
 * Then jump out of the collection loop */
static void       _collint(int s);

static void       collhup(int s);

/* ~[AaIi], *message-inject-**: put value, expand \[nt] if *posix* */
static bool_t a_coll_putesc(char const *s, bool_t addnl, FILE *stream);

/* *on-compose-splice* driver and *on-compose-splice(-shell)?* finalizer */
static int a_coll_ocs__mac(void);
static void a_coll_ocs__finalize(void *vp);

static void
_execute_command(struct header *hp, char const *linebuf, size_t linesize){
   /* The problem arises if there are rfc822 message attachments and the
    * user uses `~:' to change the current file.  TODO Unfortunately we
    * TODO cannot simply keep a pointer to, or increment a reference count
    * TODO of the current `file' (mailbox that is) object, because the
    * TODO codebase doesn't deal with that at all; so, until some far
    * TODO later time, copy the name of the path, and warn the user if it
    * TODO changed; we COULD use the AC_TMPFILE attachment type, i.e.,
    * TODO copy the message attachments over to temporary files, but that
    * TODO would require more changes so that the user still can recognize
    * TODO in `~@' etc. that its a rfc822 message attachment; see below */
   struct n_sigman sm;
   struct attachment *ap;
   char * volatile mnbuf;
   NYD_ENTER;

   n_UNUSED(linesize);
   mnbuf = NULL;

   n_SIGMAN_ENTER_SWITCH(&sm, n_SIGMAN_HUP | n_SIGMAN_INT | n_SIGMAN_QUIT){
   case 0:
      break;
   default:
      n_pstate_err_no = n_ERR_INTR;
      n_pstate_ex_no = 1;
      goto jleave;
   }

   /* If the above todo is worked, remove or outsource to attachment.c! */
   if(hp != NULL && (ap = hp->h_attach) != NULL) do
      if(ap->a_msgno){
         mnbuf = sstrdup(mailname);
         break;
      }
   while((ap = ap->a_flink) != NULL);

   n_go_command(n_GO_INPUT_CTX_COMPOSE, linebuf);

   n_sigman_cleanup_ping(&sm);
jleave:
   if(mnbuf != NULL){
      if(strcmp(mnbuf, mailname))
         n_err(_("Mailbox changed: it is likely that existing "
            "rfc822 attachments became invalid!\n"));
      n_free(mnbuf);
   }
   NYD_LEAVE;
   n_sigman_leave(&sm, n_SIGMAN_VIPSIGS_NTTYOUT);
}

static si32_t
a_coll_include_file(char const *name, bool_t indent, bool_t writestat){
   FILE *fbuf;
   char const *heredb, *indb;
   size_t linesize, heredl, indl, cnt, linelen;
   char *linebuf;
   si64_t lc, cc;
   si32_t rv;
   NYD_ENTER;

   rv = n_ERR_NONE;
   lc = cc = 0;
   linebuf = NULL; /* TODO line pool */
   linesize = 0;
   heredb = NULL;
   heredl = 0;

   /* The -M case is special */
   if(name == (char*)-1){
      fbuf = n_stdin;
      name = "-";
   }else if(name[0] == '-' &&
         (name[1] == '\0' || blankspacechar(name[1]))){
      fbuf = n_stdin;
      if(name[1] == '\0'){
         if(!(n_psonce & n_PSO_INTERACTIVE)){
            n_err(_("~< -: HERE-delimiter required in non-interactive mode\n"));
            rv = n_ERR_INVAL;
            goto jleave;
         }
      }else{
         for(heredb = &name[2]; *heredb != '\0' && blankspacechar(*heredb);
               ++heredb)
            ;
         if((heredl = strlen(heredb)) == 0){
jdelim_empty:
            n_err(_("~< - HERE-delimiter: delimiter must not be empty\n"));
            rv = n_ERR_INVAL;
            goto jleave;
         }

         if(*heredb == '\''){
            for(indb = ++heredb; *indb != '\0' && *indb != '\''; ++indb)
               ;
            if(*indb == '\0'){
               n_err(_("~< - HERE-delimiter: missing trailing quote\n"));
               rv = n_ERR_INVAL;
               goto jleave;
            }else if(indb[1] != '\0'){
               n_err(_("~< - HERE-delimiter: trailing characters after "
                  "quote\n"));
               rv = n_ERR_INVAL;
               goto jleave;
            }
            if((heredl = PTR2SIZE(indb - heredb)) == 0)
               goto jdelim_empty;
            heredb = savestrbuf(heredb, heredl);
         }
      }
      name = "-";
   }else if((fbuf = Fopen(name, "r")) == NULL){
      n_perr(name, rv = n_err_no);
      goto jleave;
   }

   indl = indent ? strlen(indb = ok_vlook(indentprefix)) : 0;

   if(fbuf != n_stdin)
      cnt = fsize(fbuf);
   while(fgetline(&linebuf, &linesize, (fbuf == n_stdin ? NULL : &cnt),
         &linelen, fbuf, 0) != NULL){
      if(heredl > 0 && heredl == linelen - 1 &&
            !memcmp(heredb, linebuf, heredl)){
         heredb = NULL;
         break;
      }

      if(indl > 0){
         if(fwrite(indb, sizeof *indb, indl, _coll_fp) != indl){
            rv = n_err_no;
            goto jleave;
         }
         cc += indl;
      }

      if(fwrite(linebuf, sizeof *linebuf, linelen, _coll_fp) != linelen){
         rv = n_err_no;
         goto jleave;
      }
      cc += linelen;
      ++lc;
   }
   if(fflush(_coll_fp)){
      rv = n_err_no;
      goto jleave;
   }

   if(heredb != NULL)
      rv = n_ERR_NOTOBACCO;
jleave:
   if(linebuf != NULL)
      n_free(linebuf);
   if(fbuf != NULL){
      if(fbuf != n_stdin)
         Fclose(fbuf);
      else if(heredl > 0)
         clearerr(n_stdin);
   }

   if(writestat)
      fprintf(n_stdout, "%s%s %" PRId64 "/%" PRId64 "\n",
         n_shexp_quote_cp(name, FAL0), (rv ? " " n_ERROR : n_empty), lc, cc);
   NYD_LEAVE;
   return rv;
}

static si32_t
a_coll_insert_cmd(FILE *fp, char const *cmd){
   FILE *ibuf;
   si64_t lc, cc;
   si32_t rv;
   NYD_ENTER;

   rv = n_ERR_NONE;
   lc = cc = 0;

   if((ibuf = Popen(cmd, "r", ok_vlook(SHELL), NULL, 0)) != NULL){
      int c;

      while((c = getc(ibuf)) != EOF){ /* XXX bytewise, yuck! */
         if(putc(c, fp) == EOF){
            rv = n_err_no;
            break;
         }
         ++cc;
         if(c == '\n')
            ++lc;
      }
      if(!feof(ibuf) || ferror(ibuf)){
         if(rv == n_ERR_NONE)
            rv = n_ERR_IO;
      }
      if(!Pclose(ibuf, TRU1)){
         if(rv == n_ERR_NONE)
            rv = n_ERR_IO;
      }
   }else
      n_perr(cmd, rv = n_err_no);

   fprintf(n_stdout, "CMD%s %" PRId64 "/%" PRId64 "\n",
      (rv == n_ERR_NONE ? n_empty : " " n_ERROR), lc, cc);
   NYD_LEAVE;
   return rv;
}

static void
print_collf(FILE *cf, struct header *hp)
{
   char *lbuf;
   FILE *obuf;
   size_t cnt, linesize, linelen;
   NYD_ENTER;

   fflush_rewind(cf);
   cnt = (size_t)fsize(cf);

   if((obuf = Ftmp(NULL, "collfp", OF_RDWR | OF_UNLINK | OF_REGISTER)) == NULL){
      n_perr(_("Can't create temporary file for `~p' command"), 0);
      goto jleave;
   }

   hold_all_sigs();

   fprintf(obuf, _("-------\nMessage contains:\n")); /* xxx SEARCH112 */
   puthead(TRU1, hp, obuf,
      (GIDENT | GTO | GSUBJECT | GCC | GBCC | GNL | GFILES | GCOMMA),
      SEND_TODISP, CONV_NONE, NULL, NULL);

   lbuf = NULL;
   linesize = 0;
   while(fgetline(&lbuf, &linesize, &cnt, &linelen, cf, 1))
      prout(lbuf, linelen, obuf);
   if(lbuf != NULL)
      n_free(lbuf);

   if(hp->h_attach != NULL){
      fputs(_("-------\nAttachments:\n"), obuf);
      n_attachment_list_print(hp->h_attach, obuf);
   }

   rele_all_sigs();

   page_or_print(obuf, 0);

   Fclose(obuf);
jleave:
   NYD_LEAVE;
}

static si32_t
a_coll_write(char const *name, FILE *fp, int f)
{
   FILE *of;
   int c;
   si64_t lc, cc;
   si32_t rv;
   NYD_ENTER;

   rv = n_ERR_NONE;

   if(f) {
      fprintf(n_stdout, "%s ", n_shexp_quote_cp(name, FAL0));
      fflush(n_stdout);
   }

   if ((of = Fopen(name, "a")) == NULL) {
      n_perr(name, rv = n_err_no);
      goto jerr;
   }

   lc = cc = 0;
   while ((c = getc(fp)) != EOF) {
      ++cc;
      if (c == '\n')
         ++lc;
      if (putc(c, of) == EOF) {
         n_perr(name, rv = n_err_no);
         goto jerr;
      }
   }
   fprintf(n_stdout, _("%" PRId64 "/%" PRId64 "\n"), lc, cc);

jleave:
   if(of != NULL)
      Fclose(of);
   fflush(n_stdout);
   NYD_LEAVE;
   return rv;
jerr:
   putc('-', n_stdout);
   putc('\n', n_stdout);
   goto jleave;
}

static bool_t
a_coll_message_inject_head(FILE *fp){
   bool_t rv;
   char const *cp, *cp_obsolete;
   NYD2_ENTER;

   cp_obsolete = ok_vlook(NAIL_HEAD);
   if(cp_obsolete != NULL)
      n_OBSOLETE(_("please use *message-inject-head*, not *NAIL_HEAD*"));

   if(((cp = ok_vlook(message_inject_head)) != NULL ||
         (cp = cp_obsolete) != NULL) && !a_coll_putesc(cp, TRU1, fp))
      rv = FAL0;
   else
      rv = TRU1;
   NYD2_LEAVE;
   return rv;
}

static bool_t
a_coll_makeheader(FILE *fp, struct header *hp, si8_t *checkaddr_err,
   bool_t do_delayed_due_t)
{
   FILE *nf;
   int c;
   bool_t rv;
   NYD_ENTER;

   rv = FAL0;

   if ((nf = Ftmp(NULL, "colhead", OF_RDWR | OF_UNLINK | OF_REGISTER)) ==NULL) {
      n_perr(_("temporary mail edit file"), 0);
      goto jleave;
   }

   n_header_extract(fp, hp, (do_delayed_due_t ? TRU1 : TRUM1), checkaddr_err);
   if (checkaddr_err != NULL && *checkaddr_err != 0)
      goto jleave;

   /* In template mode some things have been delayed until the template has
    * been read */
   if(do_delayed_due_t){
      char const *cp;

      if((cp = ok_vlook(on_compose_enter)) != NULL){
         setup_from_and_sender(hp);
         temporary_compose_mode_hook_call(cp, &n_temporary_compose_hook_varset,
            hp);
      }

      if(!a_coll_message_inject_head(nf))
         goto jleave;
   }

   while ((c = getc(fp)) != EOF) /* XXX bytewise, yuck! */
      putc(c, nf);

   if (fp != _coll_fp)
      Fclose(_coll_fp);
   Fclose(fp);
   _coll_fp = nf;
   nf = NULL;

   if (check_from_and_sender(hp->h_from, hp->h_sender) == NULL)
      goto jleave;
   rv = TRU1;
jleave:
   if(nf != NULL)
      Fclose(nf);
   NYD_LEAVE;
   return rv;
}

static si32_t
a_coll_edit(int c, struct header *hp) /* TODO error(return) weird */
{
   struct n_sigman sm;
   FILE *nf;
   sighandler_type volatile sigint;
   struct name *saved_in_reply_to;
   bool_t saved_filrec;
   si32_t volatile rv;
   NYD_ENTER;

   n_UNINIT(sigint, SIG_ERR);
   rv = n_ERR_NONE;

   if(!(saved_filrec = ok_blook(add_file_recipients)))
      ok_bset(add_file_recipients);

   saved_in_reply_to = NULL;
   if(hp != NULL){
      struct name *np;

      if((np = hp->h_in_reply_to) == NULL)
         hp->h_in_reply_to = np = n_header_setup_in_reply_to(hp);
      if(np != NULL)
         saved_in_reply_to = ndup(np, np->n_type);
   }

   n_SIGMAN_ENTER_SWITCH(&sm, n_SIGMAN_ALL){
   case 0:
      sigint = safe_signal(SIGINT, SIG_IGN);
      break;
   default:
      rv = n_ERR_INTR;
      goto jleave;
   }

   nf = run_editor(_coll_fp, (off_t)-1, c, FAL0, hp, NULL, SEND_MBOX, sigint);
   if(nf != NULL){
      if(hp != NULL){
         if(!a_coll_makeheader(nf, hp, NULL, FAL0))
            rv = n_ERR_INVAL;
         /* Break the thread if In-Reply-To: has been modified */
         if(hp->h_in_reply_to == NULL || (saved_in_reply_to != NULL &&
               asccasecmp(hp->h_in_reply_to->n_fullname,
                  saved_in_reply_to->n_fullname)))
               hp->h_ref = NULL;
      }else{
         fseek(nf, 0L, SEEK_END);
         Fclose(_coll_fp);
         _coll_fp = nf;
      }
   }else
      rv = n_ERR_CHILD;

   n_sigman_cleanup_ping(&sm);
jleave:
   if(!saved_filrec)
      ok_bclear(add_file_recipients);
   safe_signal(SIGINT, sigint);
   NYD_LEAVE;
   n_sigman_leave(&sm, n_SIGMAN_VIPSIGS_NTTYOUT);
   return rv;
}

static si32_t
a_coll_pipe(char const *cmd)
{
   int ws;
   FILE *nf;
   sighandler_type sigint;
   si32_t rv;
   NYD_ENTER;

   rv = n_ERR_NONE;
   sigint = safe_signal(SIGINT, SIG_IGN);

   if ((nf = Ftmp(NULL, "colpipe", OF_RDWR | OF_UNLINK | OF_REGISTER)) ==NULL) {
      n_perr(_("temporary mail edit file"), rv = n_err_no);
      goto jout;
   }

   /* stdin = current message.  stdout = new message */
   fflush(_coll_fp);
   if (n_child_run(ok_vlook(SHELL), 0, fileno(_coll_fp), fileno(nf), "-c",
         cmd, NULL, NULL, &ws) < 0 || WEXITSTATUS(ws) != 0) {
      Fclose(nf);
      rv = n_ERR_CHILD;
      goto jout;
   }

   if (fsize(nf) == 0) {
      n_err(_("No bytes from %s !?\n"), n_shexp_quote_cp(cmd, FAL0));
      Fclose(nf);
      rv = n_ERR_NODATA;
      goto jout;
   }

   /* Take new files */
   fseek(nf, 0L, SEEK_END);
   Fclose(_coll_fp);
   _coll_fp = nf;
jout:
   safe_signal(SIGINT, sigint);
   NYD_LEAVE;
   return rv;
}

static si32_t
a_coll_forward(char const *ms, FILE *fp, int f)
{
   int *msgvec, rv = 0;
   struct n_ignore const *itp;
   char const *tabst;
   enum sendaction action;
   NYD_ENTER;

   msgvec = n_autorec_alloc((size_t)(msgCount + 1) * sizeof *msgvec);
   if (getmsglist(ms, msgvec, 0) < 0) {
      rv = n_ERR_NOENT; /* XXX not really, should be handled there! */
      goto jleave;
   }
   if (*msgvec == 0) {
      *msgvec = first(0, MMNORM);
      if (*msgvec == 0) {
         n_err(_("No appropriate messages\n"));
         rv = n_ERR_NOENT;
         goto jleave;
      }
      msgvec[1] = 0;
   }

   if (f == 'f' || f == 'F' || f == 'u')
      tabst = NULL;
   else
      tabst = ok_vlook(indentprefix);
   if (f == 'u' || f == 'U')
      itp = n_IGNORE_ALL;
   else
      itp = upperchar(f) ? NULL : n_IGNORE_TYPE;
   action = (upperchar(f) && f != 'U') ? SEND_QUOTE_ALL : SEND_QUOTE;

   fprintf(n_stdout, _("Interpolating:"));
   srelax_hold();
   for (; *msgvec != 0; ++msgvec) {
      struct message *mp = message + *msgvec - 1;

      touch(mp);
      fprintf(n_stdout, " %d", *msgvec);
      fflush(n_stdout);
      if (sendmp(mp, fp, itp, tabst, action, NULL) < 0) {
         n_perr(_("forward: temporary mail file"), 0);
         rv = n_ERR_IO;
         break;
      }
      srelax();
   }
   srelax_rele();
   fprintf(n_stdout, "\n");
jleave:
   NYD_LEAVE;
   return rv;
}

static bool_t
a_collect_plumbing(char const *ms, struct header *hp){
   /* TODO _collect_plumbing: instead of fields the basic headers should
    * TODO be in an array and have IDs, like in termcap etc., so then this
    * TODO could be simplified as table-walks.  Also true for arg-checks! */
   bool_t rv;
   char const *cp, *cmd[4];
   NYD2_ENTER;

   /* Protcol version for *on-compose-splice** -- update manual on change! */
#define a_COLL_PLUMBING_VERSION "0 0 1"
   cp = ms;

   /* C99 */{
      size_t i;

      for(i = 0; i < n_NELEM(cmd); ++i){ /* TODO trim+strlist_split(_ifs?)() */
         while(blankchar(*cp))
            ++cp;
         if(*cp == '\0')
            cmd[i] = NULL;
         else{
            if(i < n_NELEM(cmd) - 1)
               for(cmd[i] = cp++; *cp != '\0' && !blankchar(*cp); ++cp)
                  ;
            else{
               /* Last slot takes all the rest of the line, less trailing WS */
               for(cmd[i] = cp++; *cp != '\0'; ++cp)
                  ;
               while(blankchar(cp[-1]))
                  --cp;
            }
            cmd[i] = savestrbuf(cmd[i], PTR2SIZE(cp - cmd[i]));
         }
      }
   }

   if(n_UNLIKELY(cmd[0] == NULL))
      goto jecmd;
   if(is_asccaseprefix(cmd[0], "header"))
      rv = a_collect__plumb_header(cp, hp, cmd);
   else if(is_asccaseprefix(cmd[0], "attachment"))
      rv = a_collect__plumb_attach(cp, hp, cmd);
   else{
jecmd:
      fputs("500\n", n_stdout);
      rv = FAL0;
   }
   fflush(n_stdout);

   NYD2_LEAVE;
   return rv;
}

static bool_t
a_collect__plumb_header(char const *cp, struct header *hp,
      char const *cmd[4]){
   uiz_t i;
   struct n_header_field *hfp;
   struct name *np, **npp;
   NYD2_ENTER;

   if(cmd[1] == NULL)
      goto jdefault;

   if(is_asccaseprefix(cmd[1], "insert")){ /* TODO LOGIC BELONGS head.c
       * TODO That is: Header::factory(string) -> object (blahblah).
       * TODO I.e., as long as we don't have regular RFC compliant parsers
       * TODO which differentiate in between structured and unstructured
       * TODO header fields etc., a little workaround */
      struct name *xnp;
      si8_t aerr;
      enum expand_addr_check_mode eacm;
      enum gfield ntype;
      bool_t mult_ok;

      if(cmd[2] == NULL || cmd[3] == NULL)
         goto jecmd;

      /* Strip [\r\n] which would render a body invalid XXX all controls? */
      /* C99 */{
         char *xp, c;

         cmd[3] = xp = savestr(cmd[3]);
         for(; (c = *xp) != '\0'; ++xp)
            if(c == '\n' || c == '\r')
               *xp = ' ';
      }

      if(!asccasecmp(cmd[2], cp = "Subject")){
         if(cmd[3][0] != '\0'){
            if(hp->h_subject != NULL)
               hp->h_subject = savecatsep(hp->h_subject, ' ', cmd[3]);
            else
               hp->h_subject = n_UNCONST(cmd[3]);
            fprintf(n_stdout, "210 %s 1\n", cp);
            goto jleave;
         }else
            goto j501cp;
      }

      mult_ok = TRU1;
      ntype = GEXTRA | GFULL | GFULLEXTRA;
      eacm = EACM_STRICT;

      if(!asccasecmp(cmd[2], cp = "From")){
         npp = &hp->h_from;
jins:
         aerr = 0;
         if((np = lextract(cmd[3], ntype)) == NULL)
            goto j501cp;

         if((np = checkaddrs(np, eacm, &aerr), aerr != 0)){
            fprintf(n_stdout, "505 %s\n", cp);
            goto jleave;
         }

         /* Go to the end of the list, track whether it contains any
          * non-deleted entries */
         i = 0;
         if((xnp = *npp) != NULL)
            for(;; xnp = xnp->n_flink){
               if(!(xnp->n_type & GDEL))
                  ++i;
               if(xnp->n_flink == NULL)
                  break;
            }

         if(!mult_ok && (i != 0 || np->n_flink != NULL))
            fprintf(n_stdout, "506 %s\n", cp);
         else{
            if(xnp == NULL)
               *npp = np;
            else
               xnp->n_flink = np;
            np->n_blink = xnp;
            fprintf(n_stdout, "210 %s %" PRIuZ "\n", cp, ++i);
         }
         goto jleave;
      }
      if(!asccasecmp(cmd[2], cp = "Sender")){
         mult_ok = FAL0;
         npp = &hp->h_sender;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "To")){
         npp = &hp->h_to;
         ntype = GTO | GFULL;
         eacm = EACM_NORMAL | EAF_NAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "Cc")){
         npp = &hp->h_cc;
         ntype = GCC | GFULL;
         eacm = EACM_NORMAL | EAF_NAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "Bcc")){
         npp = &hp->h_bcc;
         ntype = GBCC | GFULL;
         eacm = EACM_NORMAL | EAF_NAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "Reply-To")){
         npp = &hp->h_reply_to;
         eacm = EACM_NONAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "Mail-Followup-To")){
         npp = &hp->h_mft;
         eacm = EACM_NONAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "Message-ID")){
         mult_ok = FAL0;
         npp = &hp->h_message_id;
         ntype = GREF;
         eacm = EACM_NONAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "References")){
         npp = &hp->h_ref;
         ntype = GREF;
         eacm = EACM_NONAME;
         goto jins;
      }
      if(!asccasecmp(cmd[2], cp = "In-Reply-To")){
         npp = &hp->h_in_reply_to;
         ntype = GREF;
         eacm = EACM_NONAME;
         goto jins;
      }

      if((cp = n_header_is_standard(cmd[2], UIZ_MAX)) != NULL){
         fprintf(n_stdout, "505 %s\n", cp);
         goto jleave;
      }

      /* Free-form header fields */
      /* C99 */{
         size_t nl, bl;
         struct n_header_field **hfpp;

         for(cp = cmd[2]; *cp != '\0'; ++cp)
            if(!fieldnamechar(*cp)){
               cp = cmd[2];
               goto j501cp;
            }

         for(i = 0, hfpp = &hp->h_user_headers; *hfpp != NULL; ++i)
            hfpp = &(*hfpp)->hf_next;

         nl = strlen(cp = cmd[2]) +1;
         bl = strlen(cmd[3]) +1;
         *hfpp = hfp = n_autorec_alloc(n_VSTRUCT_SIZEOF(struct n_header_field,
               hf_dat) + nl + bl);
         hfp->hf_next = NULL;
         hfp->hf_nl = nl - 1;
         hfp->hf_bl = bl - 1;
         memcpy(&hfp->hf_dat[0], cp, nl);
         memcpy(&hfp->hf_dat[nl], cmd[3], bl);
         fprintf(n_stdout, "210 %s %" PRIuZ "\n", &hfp->hf_dat[0], ++i);
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "list")){
jdefault:
      if(cmd[2] == NULL){
         fputs("210", n_stdout);
         if(hp->h_subject != NULL) fputs(" Subject", n_stdout);
         if(hp->h_from != NULL) fputs(" From", n_stdout);
         if(hp->h_sender != NULL) fputs(" Sender", n_stdout);
         if(hp->h_to != NULL) fputs(" To", n_stdout);
         if(hp->h_cc != NULL) fputs(" Cc", n_stdout);
         if(hp->h_bcc != NULL) fputs(" Bcc", n_stdout);
         if(hp->h_reply_to != NULL) fputs(" Reply-To", n_stdout);
         if(hp->h_mft != NULL) fputs(" Mail-Followup-To", n_stdout);
         if(hp->h_message_id != NULL) fputs(" Message-ID", n_stdout);
         if(hp->h_ref != NULL) fputs(" References", n_stdout);
         if(hp->h_in_reply_to != NULL) fputs(" In-Reply-To", n_stdout);
         if(hp->h_mailx_command != NULL) fputs(" Mailx-Command", n_stdout);
         if(hp->h_mailx_raw_to != NULL) fputs(" Mailx-Raw-To", n_stdout);
         if(hp->h_mailx_raw_cc != NULL) fputs(" Mailx-Raw-Cc", n_stdout);
         if(hp->h_mailx_raw_bcc != NULL) fputs(" Mailx-Raw-Bcc", n_stdout);
         if(hp->h_mailx_orig_from != NULL) fputs(" Mailx-Orig-From", n_stdout);
         if(hp->h_mailx_orig_to != NULL) fputs(" Mailx-Orig-To", n_stdout);
         if(hp->h_mailx_orig_cc != NULL) fputs(" Mailx-Orig-Cc", n_stdout);
         if(hp->h_mailx_orig_bcc != NULL) fputs(" Mailx-Orig-Bcc", n_stdout);

         /* Print only one instance of each free-form header */
         for(hfp = hp->h_user_headers; hfp != NULL; hfp = hfp->hf_next){
            struct n_header_field *hfpx;

            for(hfpx = hp->h_user_headers;; hfpx = hfpx->hf_next)
               if(hfpx == hfp){
                  putc(' ', n_stdout);
                  fputs(&hfp->hf_dat[0], n_stdout);
                  break;
               }else if(!asccasecmp(&hfpx->hf_dat[0], &hfp->hf_dat[0]))
                  break;
         }
         putc('\n', n_stdout);
         goto jleave;
      }

      if(cmd[3] != NULL)
         goto jecmd;

      if(!asccasecmp(cmd[2], cp = "Subject")){
         np = (hp->h_subject != NULL) ? (struct name*)-1 : NULL;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "From")){
         np = hp->h_from;
jlist:
         fprintf(n_stdout, "%s %s\n", (np == NULL ? "501" : "210"), cp);
         goto jleave;
      }
      if(!asccasecmp(cmd[2], cp = "Sender")){
         np = hp->h_sender;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "To")){
         np = hp->h_to;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Cc")){
         np = hp->h_cc;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Bcc")){
         np = hp->h_bcc;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Reply-To")){
         np = hp->h_reply_to;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mail-Followup-To")){
         np = hp->h_mft;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Message-ID")){
         np = hp->h_message_id;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "References")){
         np = hp->h_ref;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "In-Reply-To")){
         np = hp->h_in_reply_to;
         goto jlist;
      }

      if(!asccasecmp(cmd[2], cp = "Mailx-Command")){
         np = (hp->h_mailx_command != NULL) ? (struct name*)-1 : NULL;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Raw-To")){
         np = hp->h_mailx_raw_to;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Raw-Cc")){
         np = hp->h_mailx_raw_cc;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Raw-Bcc")){
         np = hp->h_mailx_raw_bcc;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-From")){
         np = hp->h_mailx_orig_from;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-To")){
         np = hp->h_mailx_orig_to;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-Cc")){
         np = hp->h_mailx_orig_cc;
         goto jlist;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-Bcc")){
         np = hp->h_mailx_orig_bcc;
         goto jlist;
      }

      /* Free-form header fields */
      for(cp = cmd[2]; *cp != '\0'; ++cp)
         if(!fieldnamechar(*cp)){
            cp = cmd[2];
            goto j501cp;
         }
      cp = cmd[2];
      for(hfp = hp->h_user_headers;; hfp = hfp->hf_next){
         if(hfp == NULL)
            goto j501cp;
         else if(!asccasecmp(cp, &hfp->hf_dat[0])){
            fprintf(n_stdout, "210 %s\n", &hfp->hf_dat[0]);
            break;
         }
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "remove")){
      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      if(!asccasecmp(cmd[2], cp = "Subject")){
         if(hp->h_subject != NULL){
            hp->h_subject = NULL;
            fprintf(n_stdout, "210 %s\n", cp);
            goto jleave;
         }else
            goto j501cp;
      }

      if(!asccasecmp(cmd[2], cp = "From")){
         npp = &hp->h_from;
jrem:
         if(*npp != NULL){
            *npp = NULL;
            fprintf(n_stdout, "210 %s\n", cp);
            goto jleave;
         }else
            goto j501cp;
      }
      if(!asccasecmp(cmd[2], cp = "Sender")){
         npp = &hp->h_sender;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "To")){
         npp = &hp->h_to;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "Cc")){
         npp = &hp->h_cc;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "Bcc")){
         npp = &hp->h_bcc;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "Reply-To")){
         npp = &hp->h_reply_to;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "Mail-Followup-To")){
         npp = &hp->h_mft;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "Message-ID")){
         npp = &hp->h_message_id;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "References")){
         npp = &hp->h_ref;
         goto jrem;
      }
      if(!asccasecmp(cmd[2], cp = "In-Reply-To")){
         npp = &hp->h_in_reply_to;
         goto jrem;
      }

      if((cp = n_header_is_standard(cmd[2], UIZ_MAX)) != NULL){
         fprintf(n_stdout, "505 %s\n", cp);
         goto jleave;
      }

      /* Free-form header fields (note j501cp may print non-normalized name) */
      /* C99 */{
         struct n_header_field **hfpp;
         bool_t any;

         for(cp = cmd[2]; *cp != '\0'; ++cp)
            if(!fieldnamechar(*cp)){
               cp = cmd[2];
               goto j501cp;
            }
         cp = cmd[2];

         for(any = FAL0, hfpp = &hp->h_user_headers; (hfp = *hfpp) != NULL;){
            if(!asccasecmp(cp, &hfp->hf_dat[0])){
               *hfpp = hfp->hf_next;
               if(!any)
                  fprintf(n_stdout, "210 %s\n", &hfp->hf_dat[0]);
               any = TRU1;
            }else
               hfpp = &hfp->hf_next;
         }
         if(!any)
            goto j501cp;
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "remove-at")){
      if(cmd[2] == NULL || cmd[3] == NULL)
         goto jecmd;

      if((n_idec_uiz_cp(&i, cmd[3], 0, NULL
               ) & (n_IDEC_STATE_EMASK | n_IDEC_STATE_CONSUMED)
            ) != n_IDEC_STATE_CONSUMED || i == 0){
         fputs("505\n", n_stdout);
         goto jleave;
      }

      if(!asccasecmp(cmd[2], cp = "Subject")){
         if(hp->h_subject != NULL && i == 1){
            hp->h_subject = NULL;
            fprintf(n_stdout, "210 %s 1\n", cp);
            goto jleave;
         }else
            goto j501cp;
      }

      if(!asccasecmp(cmd[2], cp = "From")){
         npp = &hp->h_from;
jremat:
         if((np = *npp) == NULL)
            goto j501cp;
         while(--i != 0 && np != NULL)
            np = np->n_flink;
         if(np == NULL)
            goto j501cp;

         if(np->n_blink != NULL)
            np->n_blink->n_flink = np->n_flink;
         else
            *npp = np->n_flink;
         if(np->n_flink != NULL)
            np->n_flink->n_blink = np->n_blink;

         fprintf(n_stdout, "210 %s\n", cp);
         goto jleave;
      }
      if(!asccasecmp(cmd[2], cp = "Sender")){
         npp = &hp->h_sender;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "To")){
         npp = &hp->h_to;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "Cc")){
         npp = &hp->h_cc;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "Bcc")){
         npp = &hp->h_bcc;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "Reply-To")){
         npp = &hp->h_reply_to;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "Mail-Followup-To")){
         npp = &hp->h_mft;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "Message-ID")){
         npp = &hp->h_message_id;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "References")){
         npp = &hp->h_ref;
         goto jremat;
      }
      if(!asccasecmp(cmd[2], cp = "In-Reply-To")){
         npp = &hp->h_in_reply_to;
         goto jremat;
      }

      if((cp = n_header_is_standard(cmd[2], UIZ_MAX)) != NULL){
         fprintf(n_stdout, "505 %s\n", cp);
         goto jleave;
      }

      /* Free-form header fields */
      /* C99 */{
         struct n_header_field **hfpp;

         for(cp = cmd[2]; *cp != '\0'; ++cp)
            if(!fieldnamechar(*cp)){
               cp = cmd[2];
               goto j501cp;
            }
         cp = cmd[2];

         for(hfpp = &hp->h_user_headers; (hfp = *hfpp) != NULL;){
            if(--i == 0){
               *hfpp = hfp->hf_next;
               fprintf(n_stdout, "210 %s %" PRIuZ "\n", &hfp->hf_dat[0], i);
               break;
            }else
               hfpp = &hfp->hf_next;
         }
         if(hfp == NULL)
            goto j501cp;
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "show")){
      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      if(!asccasecmp(cmd[2], cp = "Subject")){
         if(hp->h_subject == NULL)
            goto j501cp;
         fprintf(n_stdout, "212 %s\n%s\n\n", cp, hp->h_subject);
         goto jleave;
      }

      if(!asccasecmp(cmd[2], cp = "From")){
         np = hp->h_from;
jshow:
         if(np != NULL){
            fprintf(n_stdout, "211 %s\n", cp);
            do if(!(np->n_type & GDEL))
               fprintf(n_stdout, "%s %s\n", np->n_name, np->n_fullname);
            while((np = np->n_flink) != NULL);
            putc('\n', n_stdout);
            goto jleave;
         }else
            goto j501cp;
      }
      if(!asccasecmp(cmd[2], cp = "Sender")){
         np = hp->h_sender;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "To")){
         np = hp->h_to;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Cc")){
         np = hp->h_cc;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Bcc")){
         np = hp->h_bcc;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Reply-To")){
         np = hp->h_reply_to;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mail-Followup-To")){
         np = hp->h_mft;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Message-ID")){
         np = hp->h_message_id;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "References")){
         np = hp->h_ref;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "In-Reply-To")){
         np = hp->h_in_reply_to;
         goto jshow;
      }

      if(!asccasecmp(cmd[2], cp = "Mailx-Command")){
         if(hp->h_mailx_command == NULL)
            goto j501cp;
         fprintf(n_stdout, "212 %s\n%s\n\n", cp, hp->h_mailx_command);
         goto jleave;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Raw-To")){
         np = hp->h_mailx_raw_to;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Raw-Cc")){
         np = hp->h_mailx_raw_cc;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Raw-Bcc")){
         np = hp->h_mailx_raw_bcc;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-From")){
         np = hp->h_mailx_orig_from;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-To")){
         np = hp->h_mailx_orig_to;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-Cc")){
         np = hp->h_mailx_orig_cc;
         goto jshow;
      }
      if(!asccasecmp(cmd[2], cp = "Mailx-Orig-Bcc")){
         np = hp->h_mailx_orig_bcc;
         goto jshow;
      }

      /* Free-form header fields */
      /* C99 */{
         bool_t any;

         for(cp = cmd[2]; *cp != '\0'; ++cp)
            if(!fieldnamechar(*cp)){
               cp = cmd[2];
               goto j501cp;
            }
         cp = cmd[2];

         for(any = FAL0, hfp = hp->h_user_headers; hfp != NULL;
               hfp = hfp->hf_next){
            if(!asccasecmp(cp, &hfp->hf_dat[0])){
               if(!any)
                  fprintf(n_stdout, "212 %s\n", &hfp->hf_dat[0]);
               any = TRU1;
               fprintf(n_stdout, "%s\n", &hfp->hf_dat[hfp->hf_nl +1]);
            }
         }
         if(any)
            putc('\n', n_stdout);
         else
            goto j501cp;
      }
      goto jleave;
   }

jecmd:
   fputs("500\n", n_stdout);
   cp = NULL;
jleave:
   NYD2_LEAVE;
   return (cp != NULL);

j501cp:
   fputs("501 ", n_stdout);
   fputs(cp, n_stdout);
   putc('\n', n_stdout);
   goto jleave;
}

static bool_t
a_collect__plumb_attach(char const *cp, struct header *hp,
      char const *cmd[4]){
   bool_t status;
   struct attachment *ap;
   NYD2_ENTER;

   if(cmd[1] == NULL)
      goto jdefault;

   if(is_asccaseprefix(cmd[1], "attribute")){
      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      if((ap = n_attachment_find(hp->h_attach, cmd[2], NULL)) != NULL){
jatt_att:
         fprintf(n_stdout, "212 %s\n", cmd[2]);
         if(ap->a_msgno > 0)
            fprintf(n_stdout, "message-number %d\n\n", ap->a_msgno);
         else{
            fprintf(n_stdout,
               "creation-name %s\nopen-path %s\nfilename %s\n",
               ap->a_path_user, ap->a_path, ap->a_name);
            if(ap->a_content_description != NULL)
               fprintf(n_stdout, "content-description %s\n",
                  ap->a_content_description);
            if(ap->a_content_id != NULL)
               fprintf(n_stdout, "content-id %s\n",
                  ap->a_content_id->n_name);
            if(ap->a_content_type != NULL)
               fprintf(n_stdout, "content-type %s\n", ap->a_content_type);
            if(ap->a_content_disposition != NULL)
               fprintf(n_stdout, "content-disposition %s\n",
                  ap->a_content_disposition);
            putc('\n', n_stdout);
         }
      }else
         fputs("501\n", n_stdout);
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "attribute-at")){
      uiz_t i;

      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      if((n_idec_uiz_cp(&i, cmd[2], 0, NULL
               ) & (n_IDEC_STATE_EMASK | n_IDEC_STATE_CONSUMED)
            ) != n_IDEC_STATE_CONSUMED || i == 0)
         fputs("505\n", n_stdout);
      else{
         for(ap = hp->h_attach; ap != NULL && --i != 0; ap = ap->a_flink)
            ;
         if(ap != NULL)
            goto jatt_att;
         else
            fputs("501\n", n_stdout);
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "attribute-set")){
      if(cmd[2] == NULL || cmd[3] == NULL)
         goto jecmd;

      if((ap = n_attachment_find(hp->h_attach, cmd[2], NULL)) != NULL){
jatt_attset:
         if(ap->a_msgno > 0)
            fputs("505\n", n_stdout);
         else{
            char c, *keyw;

            cp = cmd[3];
            while((c = *cp) != '\0' && !blankchar(c))
               ++cp;
            keyw = savestrbuf(cmd[3], PTR2SIZE(cp - cmd[3]));
            if(c != '\0'){
               for(; (c = *++cp) != '\0' && blankchar(c);)
                  ;
               if(c != '\0'){
                  char *xp;

                  /* Strip [\r\n] which would render a parameter invalid XXX
                   * XXX all controls? */
                  cp = xp = savestr(cp);
                  for(; (c = *xp) != '\0'; ++xp)
                     if(c == '\n' || c == '\r')
                        *xp = ' ';
                  c = *cp;
               }
            }

            if(!asccasecmp(keyw, "filename"))
               ap->a_name = (c == '\0') ? ap->a_path_bname : cp;
            else if(!asccasecmp(keyw, "content-description"))
               ap->a_content_description = (c == '\0') ? NULL : cp;
            else if(!asccasecmp(keyw, "content-id")){
               ap->a_content_id = NULL;

               if(c != '\0'){
                  struct name *np;

                  np = checkaddrs(lextract(cp, GREF),
                        /*EACM_STRICT | TODO '/' valid!! */ EACM_NOLOG |
                        EACM_NONAME, NULL);
                  if(np != NULL && np->n_flink == NULL)
                     ap->a_content_id = np;
                  else
                     cp = NULL;
               }
            }else if(!asccasecmp(keyw, "content-type"))
               ap->a_content_type = (c == '\0') ? NULL : cp;
            else if(!asccasecmp(keyw, "content-disposition"))
               ap->a_content_disposition = (c == '\0') ? NULL : cp;
            else
               cp = NULL;

            if(cp != NULL){
               size_t i;

               for(i = 0; ap != NULL; ++i, ap = ap->a_blink)
                  ;
               fprintf(n_stdout, "210 %" PRIuZ "\n", i);
            }else
               fputs("505\n", n_stdout);
         }
      }else
         fputs("501\n", n_stdout);
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "attribute-set-at")){
      uiz_t i;

      if(cmd[2] == NULL || cmd[3] == NULL)
         goto jecmd;

      if((n_idec_uiz_cp(&i, cmd[2], 0, NULL
               ) & (n_IDEC_STATE_EMASK | n_IDEC_STATE_CONSUMED)
            ) != n_IDEC_STATE_CONSUMED || i == 0)
         fputs("505\n", n_stdout);
      else{
         for(ap = hp->h_attach; ap != NULL && --i != 0; ap = ap->a_flink)
            ;
         if(ap != NULL)
            goto jatt_attset;
         else
            fputs("501\n", n_stdout);
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "insert")){
      enum n_attach_error aerr;

      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      hp->h_attach = n_attachment_append(hp->h_attach, cmd[2], &aerr, &ap);
      switch(aerr){
      case n_ATTACH_ERR_FILE_OPEN: cp = "505\n"; goto jatt_ins;
      case n_ATTACH_ERR_ICONV_FAILED: cp = "506\n"; goto jatt_ins;
      case n_ATTACH_ERR_ICONV_NAVAIL:
      case n_ATTACH_ERR_OTHER:
      default:
         cp = "501\n";
jatt_ins:
         fputs(cp, n_stdout);
         break;
      case n_ATTACH_ERR_NONE:{
         size_t i;

         for(i = 0; ap != NULL; ++i, ap = ap->a_blink)
            ;
         fprintf(n_stdout, "210 %" PRIuZ "\n", i);
         }break;
      }
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "list")){
jdefault:
      if(cmd[2] != NULL)
         goto jecmd;

      if((ap = hp->h_attach) != NULL){
         fputs("212\n", n_stdout);
         do
            fprintf(n_stdout, "%s\n", ap->a_path_user);
         while((ap = ap->a_flink) != NULL);
         putc('\n', n_stdout);
      }else
         fputs("501\n", n_stdout);
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "remove")){
      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      if((ap = n_attachment_find(hp->h_attach, cmd[2], &status)) != NULL){
         if(status == TRUM1)
            fputs("506\n", n_stdout);
         else{
            hp->h_attach = n_attachment_remove(hp->h_attach, ap);
            fprintf(n_stdout, "210 %s\n", cmd[2]);
         }
      }else
         fputs("501\n", n_stdout);
      goto jleave;
   }

   if(is_asccaseprefix(cmd[1], "remove-at")){
      uiz_t i;

      if(cmd[2] == NULL || cmd[3] != NULL)
         goto jecmd;

      if((n_idec_uiz_cp(&i, cmd[2], 0, NULL
               ) & (n_IDEC_STATE_EMASK | n_IDEC_STATE_CONSUMED)
            ) != n_IDEC_STATE_CONSUMED || i == 0)
         fputs("505\n", n_stdout);
      else{
         for(ap = hp->h_attach; ap != NULL && --i != 0; ap = ap->a_flink)
            ;
         if(ap != NULL){
            hp->h_attach = n_attachment_remove(hp->h_attach, ap);
            fprintf(n_stdout, "210 %s\n", cmd[2]);
         }else
            fputs("501\n", n_stdout);
      }
      goto jleave;
   }

jecmd:
   fputs("500\n", n_stdout);
   cp = NULL;
jleave:
   NYD2_LEAVE;
   return (cp != NULL);
}

static void
_collint(int s)
{
   NYD_X; /* Signal handler */

   /* the control flow is subtle, because we can be called from ~q */
   if (_coll_hadintr == 0) {
      if (ok_blook(ignore)) {
         fputs("@\n", n_stdout);
         fflush(n_stdout);
         clearerr(n_stdin);
      } else
         _coll_hadintr = 1;
      siglongjmp(_coll_jmp, 1);
   }
   n_exit_status |= n_EXIT_SEND_ERROR;
   if (s != 0)
      savedeadletter(_coll_fp, TRU1);
   /* Aborting message, no need to fflush() .. */
   siglongjmp(_coll_abort, 1);
}

static void
collhup(int s)
{
   NYD_X; /* Signal handler */
   n_UNUSED(s);

   savedeadletter(_coll_fp, TRU1);
   /* Let's pretend nobody else wants to clean up, a true statement at
    * this time */
   exit(n_EXIT_ERR);
}

static bool_t
a_coll_putesc(char const *s, bool_t addnl, FILE *stream){
   char c1, c2;
   bool_t isposix;
   NYD2_ENTER;

   isposix = ok_blook(posix);

   while((c1 = *s++) != '\0'){
      if(c1 == '\\' && ((c2 = *s) == 't' || c2 == 'n')){
         if(!isposix){
            isposix = TRU1; /* TODO v15 OBSOLETE! */
            n_err(_("Compose mode warning: expanding \\t or \\n in variable "
                  "without *posix*!"
               "\n  Support remains only for ~A,~a,~I,~i in *posix* mode!\n"));
         }
         ++s;
         c1 = (c2 == 't') ? '\t' : '\n';
      }

      if(putc(c1, stream) == EOF)
         goto jleave;
   }

   if(addnl && putc('\n', stream) == EOF)
      goto jleave;

jleave:
   NYD2_LEAVE;
   return (c1 == '\0');
}

static int
a_coll_ocs__mac(void){
   /* Executes in a fork(2)ed child  TODO if remains, global MASKs for those! */
   setvbuf(n_stdin, NULL, _IOLBF, 0);
   setvbuf(n_stdout, NULL, _IOLBF, 0);
   n_psonce &= ~(n_PSO_INTERACTIVE | n_PSO_TTYIN | n_PSO_TTYOUT);
   n_pstate |= n_PS_COMPOSE_FORKHOOK;
   n_readctl_overlay = NULL; /* TODO we need OnForkEvent! See c_readctl() */
   if(n_poption & n_PO_D_VV){
      char buf[128];

      snprintf(buf, sizeof buf, "[%d]%s", getpid(), ok_vlook(log_prefix));
      ok_vset(log_prefix, buf);
   }
   /* TODO If that uses `!' it will effectively SIG_IGN SIGINT, ...and such */
   temporary_compose_mode_hook_call(a_coll_ocs__macname, NULL, NULL);
   return 0;
}

static void
a_coll_ocs__finalize(void *vp){
   /* Note we use this for destruction upon setup errors, thus */
   sighandler_type opipe;
   sighandler_type oint;
   struct a_coll_ocs_arg **coapp, *coap;
   NYD2_ENTER;

   temporary_compose_mode_hook_call((char*)-1, NULL, NULL);

   coap = *(coapp = vp);
   *coapp = (struct a_coll_ocs_arg*)-1;

   if(coap->coa_stdin != NULL)
      Fclose(coap->coa_stdin);
   else if(coap->coa_pipe[0] != -1)
      close(coap->coa_pipe[0]);

   if(coap->coa_stdout != NULL && !Pclose(coap->coa_stdout, TRU1))
      *coap->coa_senderr = 111;
   if(coap->coa_pipe[1] != -1)
      close(coap->coa_pipe[1]);

   opipe = coap->coa_opipe;
   oint = coap->coa_oint;

   n_lofi_free(coap);

   hold_all_sigs();
   safe_signal(SIGPIPE, opipe);
   safe_signal(SIGINT, oint);
   rele_all_sigs();
   NYD2_LEAVE;
}

FL void
n_temporary_compose_hook_varset(void *arg){ /* TODO v15: drop */
   struct header *hp;
   char const *val;
   NYD2_ENTER;

   hp = arg;

   if((val = hp->h_subject) == NULL)
      val = n_empty;
   ok_vset(mailx_subject, val);
   if((val = detract(hp->h_from, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_from, val);
   if((val = detract(hp->h_sender, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_sender, val);
   if((val = detract(hp->h_to, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_to, val);
   if((val = detract(hp->h_cc, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_cc, val);
   if((val = detract(hp->h_bcc, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_bcc, val);

   if((val = hp->h_mailx_command) == NULL)
      val = n_empty;
   ok_vset(mailx_command, val);

   if((val = detract(hp->h_mailx_raw_to, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_raw_to, val);
   if((val = detract(hp->h_mailx_raw_cc, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_raw_cc, val);
   if((val = detract(hp->h_mailx_raw_bcc, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_raw_bcc, val);

   if((val = detract(hp->h_mailx_orig_from, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_orig_from, val);
   if((val = detract(hp->h_mailx_orig_to, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_orig_to, val);
   if((val = detract(hp->h_mailx_orig_cc, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_orig_cc, val);
   if((val = detract(hp->h_mailx_orig_bcc, GNAMEONLY)) == NULL)
      val = n_empty;
   ok_vset(mailx_orig_bcc, val);
   NYD2_LEAVE;
}

FL FILE *
collect(struct header *hp, int printheaders, struct message *mp,
   char const *quotefile, int doprefix, si8_t *checkaddr_err)
{
   struct n_string s, * volatile sp;
   struct n_ignore const *quoteitp;
   struct a_coll_ocs_arg *coap;
   int c;
   int volatile t, eofcnt, getfields;
   char volatile escape;
   enum{
      a_NONE,
      a_ERREXIT = 1u<<0,
      a_IGNERR = 1u<<1,
      a_COAP_NOSIGTERM = 1u<<8
#define a_HARDERR() ((flags & (a_ERREXIT | a_IGNERR)) == a_ERREXIT)
   } volatile flags;
   char *linebuf;
   char const *cp, *cp_base, * volatile coapm, * volatile ifs_saved;
   size_t i, linesize; /* TODO line pool */
   long cnt;
   enum sendaction action;
   sigset_t oset, nset;
   FILE * volatile sigfp;
   NYD_ENTER;

   _coll_fp = NULL;
   sigfp = NULL;
   linesize = 0;
   linebuf = NULL;
   flags = a_NONE;
   eofcnt = 0;
   ifs_saved = coapm = NULL;
   coap = NULL;
   sp = NULL;

   /* Start catching signals from here, but we're still die on interrupts
    * until we're in the main loop */
   sigfillset(&nset);
   sigprocmask(SIG_BLOCK, &nset, &oset);
   if ((_coll_saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
      safe_signal(SIGINT, &_collint);
   if ((_coll_savehup = safe_signal(SIGHUP, SIG_IGN)) != SIG_IGN)
      safe_signal(SIGHUP, collhup);
   if (sigsetjmp(_coll_abort, 1))
      goto jerr;
   if (sigsetjmp(_coll_jmp, 1))
      goto jerr;
   n_pstate |= n_PS_COMPOSE_MODE;
   sigprocmask(SIG_SETMASK, &oset, (sigset_t*)NULL);

   if ((_coll_fp = Ftmp(NULL, "collect", OF_RDWR | OF_UNLINK | OF_REGISTER)) ==
         NULL) {
      n_perr(_("collect: temporary mail file"), 0);
      goto jerr;
   }

   /* If we are going to prompt for a subject, refrain from printing a newline
    * after the headers (since some people mind) */
   getfields = 0;
   if(!(n_poption & n_PO_t_FLAG)){
      t = GTO | GSUBJECT | GCC | GNL;
      if(ok_blook(fullnames))
         t |= GCOMMA;

      if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT)){
         if(hp->h_subject == NULL && ok_blook(asksub)/* *ask* auto warped! */)
            t &= ~GNL, getfields |= GSUBJECT;

         if(hp->h_to == NULL)
            t &= ~GNL, getfields |= GTO;

         if(!ok_blook(bsdcompat) && !ok_blook(askatend)){
            if(ok_blook(askbcc))
               t &= ~GNL, getfields |= GBCC;
            if(ok_blook(askcc))
               t &= ~GNL, getfields |= GCC;
         }
      }
   }else{
      n_UNINIT(t, 0);
   }

   _coll_hadintr = 0;

   if (!sigsetjmp(_coll_jmp, 1)) {
      /* Ask for some headers first, as necessary */
      if (getfields)
         grab_headers(n_GO_INPUT_CTX_COMPOSE, hp, getfields, 1);

      /* Execute compose-enter; delayed for -t mode */
      if(!(n_poption & n_PO_t_FLAG) &&
            (cp = ok_vlook(on_compose_enter)) != NULL){
         setup_from_and_sender(hp);
         temporary_compose_mode_hook_call(cp, &n_temporary_compose_hook_varset,
            hp);
      }

      /* TODO Mm: nope since it may require turning this into a multipart one */
      if(!(n_poption & (n_PO_Mm_FLAG | n_PO_t_FLAG))){
         if(!a_coll_message_inject_head(_coll_fp))
            goto jerr;

         /* Quote an original message */
         if (mp != NULL && (doprefix || (cp = ok_vlook(quote)) != NULL)) {
            quoteitp = n_IGNORE_ALL;
            action = SEND_QUOTE;
            if (doprefix) {
               char const *cp_v15compat;

               quoteitp = n_IGNORE_FWD;

               if((cp_v15compat = ok_vlook(fwdheading)) != NULL)
                  n_OBSOLETE(_("please use *forward-inject-head*, "
                     "not *fwdheading*"));
               cp = ok_vlook(forward_inject_head);
               if(cp == NULL && (cp = cp_v15compat) == NULL)
                  cp = "-------- Original Message --------";
               if (*cp != '\0' && fprintf(_coll_fp, "%s\n", cp) < 0)
                  goto jerr;
            } else if (!strcmp(cp, "noheading")) {
               /*EMPTY*/;
            } else if (!strcmp(cp, "headers")) {
               quoteitp = n_IGNORE_TYPE;
            } else if (!strcmp(cp, "allheaders")) {
               quoteitp = NULL;
               action = SEND_QUOTE_ALL;
            } else {
               cp = hfield1("from", mp);
               if (cp != NULL && (cnt = (long)strlen(cp)) > 0) {
                  if (xmime_write(cp, cnt, _coll_fp, CONV_FROMHDR, TD_NONE,
                        NULL, NULL) < 0)
                     goto jerr;
                  if (fprintf(_coll_fp, _(" wrote:\n\n")) < 0)
                     goto jerr;
               }
            }
            if (fflush(_coll_fp))
               goto jerr;
            if (sendmp(mp, _coll_fp, quoteitp,
                  (doprefix ? NULL : ok_vlook(indentprefix)),
                  action, NULL) < 0)
               goto jerr;
         }
      }

      if (quotefile != NULL) {
         if((n_pstate_err_no = a_coll_include_file(quotefile, FAL0, FAL0)
               ) != n_ERR_NONE)
            goto jerr;
      }

      if(n_psonce & n_PSO_INTERACTIVE){
         if(!(n_pstate & n_PS_SOURCING)){
            sp = n_string_creat_auto(&s);
            sp = n_string_reserve(sp, 80);
         }

         if(!(n_poption & n_PO_Mm_FLAG) && !(n_pstate & n_PS_ROBOT)){
            /* Print what we have sofar also on the terminal (if useful) */
            if((cp = ok_vlook(editalong)) == NULL){
               if (printheaders)
                  puthead(TRU1, hp, n_stdout, t,
                     SEND_TODISP, CONV_NONE, NULL, NULL);

               rewind(_coll_fp);
               while ((c = getc(_coll_fp)) != EOF) /* XXX bytewise, yuck! */
                  putc(c, n_stdout);
               if (fseek(_coll_fp, 0, SEEK_END))
                  goto jerr;
            }else{
               rewind(_coll_fp);
               if(a_coll_edit(((*cp == 'v') ? 'v' : 'e'), hp) != n_ERR_NONE)
                  goto jerr;
               /* Print msg mandated by the Mail Reference Manual */
jcont:
               if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT))
                  fputs(_("(continue)\n"), n_stdout);
            }
            fflush(n_stdout);
         }
      }
   } else {
      /* Come here for printing the after-signal message.  Duplicate messages
       * won't be printed because the write is aborted if we get a SIGTTOU */
      if(_coll_hadintr && (n_psonce & n_PSO_INTERACTIVE) &&
            !(n_pstate & n_PS_ROBOT))
         n_err(_("\n(Interrupt -- one more to kill letter)\n"));
   }

   /* If not under shell hook control */
   if(coap == NULL){
      /* We're done with -M or -m TODO because: we are too stupid yet, above */
      if(n_poption & n_PO_Mm_FLAG)
         goto jout;
      /* No command escapes, interrupts not expected.  Simply copy STDIN */
      if(!(n_psonce & n_PSO_INTERACTIVE) &&
            !(n_poption & (n_PO_t_FLAG | n_PO_TILDE_FLAG))){
         linebuf = n_realloc(linebuf, linesize = LINESIZE);
         while ((i = fread(linebuf, sizeof *linebuf, linesize, n_stdin)) > 0) {
            if (i != fwrite(linebuf, sizeof *linebuf, i, _coll_fp))
               goto jerr;
         }
         goto jout;
      }
   }

   /* The interactive collect loop */
   if(coap == NULL)
      escape = *ok_vlook(escape);
   flags = ok_blook(errexit) ? a_ERREXIT : a_NONE;

   for(;;){
      enum {a_HIST_NONE, a_HIST_ADD = 1u<<0, a_HIST_GABBY = 1u<<1} hist;

      /* C99 */{
         enum n_go_input_flags gif;
         bool_t histadd;

         /* TODO optimize: no need to evaluate that anew for each loop tick! */
         gif = n_GO_INPUT_CTX_COMPOSE;
         histadd = (sp != NULL);
         if((n_psonce & n_PSO_INTERACTIVE) || (n_poption & n_PO_TILDE_FLAG)){
            if(!(n_poption & n_PO_t_FLAG) || (n_psonce & n_PSO_t_FLAG_DONE))
               gif |= n_GO_INPUT_NL_ESC;
         }
         cnt = n_go_input(gif, n_empty, &linebuf, &linesize, NULL, &histadd);
         hist = histadd ? a_HIST_ADD | a_HIST_GABBY : a_HIST_NONE;
      }

      if(cnt < 0){
         if(coap != NULL)
            break;
         if((n_poption & n_PO_t_FLAG) && !(n_psonce & n_PSO_t_FLAG_DONE)){
            fflush_rewind(_coll_fp);
            n_psonce |= n_PSO_t_FLAG_DONE;
            if(!a_coll_makeheader(_coll_fp, hp, checkaddr_err, TRU1))
               goto jerr;
            continue;
         }else if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT) &&
               ok_blook(ignoreeof) && ++eofcnt < 4){
            fprintf(n_stdout,
               _("*ignoreeof* set, use `~.' to terminate letter\n"));
            n_go_input_clearerr();
            continue;
         }
         break;
      }

      _coll_hadintr = 0;

      cp = linebuf;
      if(cnt == 0)
         goto jputnl;
      else if(coap == NULL){
         if(!(n_psonce & n_PSO_INTERACTIVE) && !(n_poption & n_PO_TILDE_FLAG))
            goto jputline;
         else if(cp[0] == '.'){
            if(cnt == 1 && (ok_blook(dot) ||
                  (ok_blook(posix) && ok_blook(ignoreeof))))
               break;
         }
      }
      if(cp[0] != escape){
jputline:
         if(fwrite(cp, sizeof *cp, cnt, _coll_fp) != (size_t)cnt)
            goto jerr;
         /* TODO n_PS_READLINE_NL is a terrible hack to ensure that _in_all_-
          * TODO _code_paths_ a file without trailing newline isn't modified
          * TODO to contain one; the "saw-newline" needs to be part of an
          * TODO I/O input machinery object */
jputnl:
         if(n_pstate & n_PS_READLINE_NL){
            if(putc('\n', _coll_fp) == EOF)
               goto jerr;
         }
         continue;
      }

      c = *(cp_base = ++cp);
      if(--cnt == 0)
         goto jearg;

      /* Avoid history entry? */
      while(spacechar(c)){
         hist = a_HIST_NONE;
         c = *(cp_base = ++cp);
         if(--cnt == 0)
            goto jearg;
      }

      /* It may just be an escaped escaped character, do that quick */
      if(c == escape)
         goto jputline;

      /* Avoid hard *errexit*? */
      flags &= ~a_IGNERR;
      if(c == '-'){
         flags ^= a_IGNERR;
         c = *++cp;
         if(--cnt == 0)
            goto jearg;
      }

      /* Trim input, also to gain a somewhat normalized history entry */
      ++cp;
      if(--cnt > 0){
         struct str x;

         x.s = n_UNCONST(cp);
         x.l = (size_t)cnt;
         n_str_trim_ifs(&x, TRU1);
         x.s[x.l] = '\0';
         cp = x.s;
         cnt = (int)/*XXX*/x.l;
      }

      if(hist != a_HIST_NONE){
         sp = n_string_assign_c(sp, escape);
         if(flags & a_IGNERR)
            sp = n_string_push_c(sp, '-');
         sp = n_string_push_c(sp, c);
         if(cnt > 0){
            sp = n_string_push_c(sp, ' ');
            sp = n_string_push_buf(sp, cp, cnt);
         }
      }

      /* Switch over all command escapes */
      switch(c){
      default:
         if(1){
            char buf[sizeof(n_UNIREPL)];

            if(asciichar(c))
               buf[0] = c, buf[1] = '\0';
            else if(n_psonce & n_PSO_UNICODE)
               memcpy(buf, n_unirepl, sizeof n_unirepl);
            else
               buf[0] = '?', buf[1] = '\0';
            n_err(_("Unknown command escape: `%c%s'\n"), escape, buf);
         }else
jearg:
            n_err(_("Invalid command escape usage: %s\n"),
               n_shexp_quote_cp(linebuf, FAL0));
         if(a_HARDERR())
            goto jerr;
         n_pstate_err_no = n_ERR_INVAL;
         n_pstate_ex_no = 1;
         continue;
      case '!':
         /* Shell escape, send the balance of line to sh -c */
         if(cnt == 0 || coap != NULL)
            goto jearg;
         else{
            char const *argv[2];

            argv[0] = cp;
            argv[1] = NULL;
            n_pstate_ex_no = c_shell(argv); /* TODO history norm.; errexit? */
         }
         goto jhistcont;
      case '.':
         /* Simulate end of file on input */
         if(cnt != 0 || coap != NULL)
            goto jearg;
         goto jout; /* TODO does not enter history, thus */
      case ':':
      case '_':
         /* Escape to command mode, but be nice! *//* TODO command expansion
          * TODO should be handled here so that we have unique history! */
         if(cnt == 0)
            goto jearg;
         _execute_command(hp, cp, cnt);
         if(ok_blook(errexit))
            flags |= a_ERREXIT;
         else
            flags &= ~a_ERREXIT;
         if(n_pstate_ex_no != 0 && a_HARDERR())
            goto jerr;
         if(coap == NULL)
            escape = *ok_vlook(escape);
         hist &= ~a_HIST_GABBY;
         break;
      /* case '<': <> 'd' */
      case '?':
#ifdef HAVE_UISTRINGS
         fputs(_(
"COMMAND ESCAPES (to be placed after a newline) excerpt:\n"
"~.            Commit and send message\n"
"~: <command>  Execute an internal command\n"
"~< <file>     Insert <file> (\"~<! <command>\" inserts shell command)\n"
"~@ [<files>]  Edit[/Add] attachments (file[=input-charset[#output-charset]])\n"
"~c <users>    Add users to Cc: list (`~b': to Bcc:)\n"
"~d            Read in $DEAD (dead.letter)\n"
"~e            Edit message via $EDITOR\n"
"~F <msglist>  Read in with headers, do not *indentprefix* lines\n"
            ), n_stdout);
         fputs(_(
"~f <msglist>  Like ~F, but honour `ignore' / `retain' configuration\n"
"~H            Edit From:, Reply-To: and Sender:\n"
"~h            Prompt for Subject:, To:, Cc: and \"blind\" Bcc:\n"
"~i <variable> Insert a value and a newline\n"
"~M <msglist>  Read in with headers, *indentprefix* (`~m': `retain' etc.)\n"
"~p            Show current message compose buffer\n"
"~r <file>     Insert <file> (`~R': likewise, but *indentprefix* lines)\n"
"              <file> may also be <- [HERE-DELIMITER]>\n"
            ), n_stdout);
         fputs(_(
"~s <subject>  Set Subject:\n"
"~t <users>    Add users to To: list\n"
"~u <msglist>  Read in message(s) without headers (`~U': indent lines)\n"
"~v            Edit message via $VISUAL\n"
"~w <file>     Write message onto file\n"
"~x            Abort composition, discard message (`~q': save in $DEAD)\n"
"~| <command>  Pipe message through shell filter\n"
            ), n_stdout);
#endif /* HAVE_UISTRINGS */
         if(cnt != 0)
            goto jearg;
         n_pstate_err_no = n_ERR_NONE;
         n_pstate_ex_no = 0;
         break;
      case '@':{
         struct attachment *aplist;

         /* Edit the attachment list */
         aplist = hp->h_attach;
         hp->h_attach = NULL;
         if(cnt != 0)
            hp->h_attach = n_attachment_append_list(aplist, cp);
         else
            hp->h_attach = n_attachment_list_edit(aplist,
                  n_GO_INPUT_CTX_COMPOSE);
         n_pstate_err_no = n_ERR_NONE; /* XXX ~@ does NOT handle $!/$?! */
         n_pstate_ex_no = 0; /* XXX */
         }break;
      case '^':
         if(!a_collect_plumbing(cp, hp)){
            if(ferror(_coll_fp))
               goto jerr;
            goto jearg;
         }
         n_pstate_err_no = n_ERR_NONE; /* XXX */
         n_pstate_ex_no = 0; /* XXX */
         hist &= ~a_HIST_GABBY;
         break;
      /* case '_': <> ':' */
      case '|':
         /* Pipe message through command. Collect output as new message */
         if(cnt == 0)
            goto jearg;
         rewind(_coll_fp);
         if((n_pstate_err_no = a_coll_pipe(cp)) == n_ERR_NONE)
            n_pstate_ex_no = 0;
         else if(a_HARDERR())
            goto jerr;
         else
            n_pstate_ex_no = 1;
         hist &= ~a_HIST_GABBY;
         goto jhistcont;
      case 'A':
      case 'a':
         /* Insert the contents of a sign variable */
         if(cnt != 0)
            goto jearg;
         cp = (c == 'a') ? ok_vlook(sign) : ok_vlook(Sign);
         goto jIi_putesc;
      case 'b':
         /* Add stuff to blind carbon copies list TODO join 'c' */
         if(cnt == 0)
            goto jearg;
         else{
            struct name *np;
            si8_t soe;

            soe = 0;
            if((np = checkaddrs(lextract(cp, GBCC | GFULL), EACM_NORMAL, &soe)
                  ) != NULL)
               hp->h_bcc = cat(hp->h_bcc, np);
            if(soe == 0){
               n_pstate_err_no = n_ERR_NONE;
               n_pstate_ex_no = 0;
            }else{
               n_pstate_ex_no = 1;
               n_pstate_err_no = (soe < 0) ? n_ERR_PERM : n_ERR_INVAL;
            }
         }
         hist &= ~a_HIST_GABBY;
         break;
      case 'c':
         /* Add to the CC list TODO join 'b' */
         if(cnt == 0)
            goto jearg;
         else{
            struct name *np;
            si8_t soe;

            soe = 0;
            if((np = checkaddrs(lextract(cp, GCC | GFULL), EACM_NORMAL, &soe)
                  ) != NULL)
               hp->h_cc = cat(hp->h_cc, np);
            if(soe == 0){
               n_pstate_err_no = n_ERR_NONE;
               n_pstate_ex_no = 0;
            }else{
               n_pstate_ex_no = 1;
               n_pstate_err_no = (soe < 0) ? n_ERR_PERM : n_ERR_INVAL;
            }
         }
         hist &= ~a_HIST_GABBY;
         break;
      case 'd':
         if(cnt != 0)
            goto jearg;
         cp = n_getdeadletter();
         if(0){
      case '<':
      case 'R':
      case 'r':
            /* Invoke a file: Search for the file name, then open it and copy
             * the contents to _coll_fp */
            if(cnt == 0){
               n_err(_("Interpolate what file?\n"));
               if(a_HARDERR())
                  goto jerr;
               n_pstate_err_no = n_ERR_NOENT;
               n_pstate_ex_no = 1;
               break;
            }
            if(*cp == '!' && c == '<'){
               /* TODO hist. normalization */
               if((n_pstate_err_no = a_coll_insert_cmd(_coll_fp, ++cp)
                     ) != n_ERR_NONE){
                  if(ferror(_coll_fp))
                     goto jerr;
                  if(a_HARDERR())
                     goto jerr;
                  n_pstate_ex_no = 1;
                  break;
               }
               goto jhistcont;
            }
            /* Note this also expands things like
             *    !:vput vexpr delim random 0
             *    !< - $delim */
            if((cp = fexpand(cp, FEXP_LOCAL | FEXP_NOPROTO | FEXP_NSHELL)
                  ) == NULL){
               if(a_HARDERR())
                  goto jerr;
               n_pstate_err_no = n_ERR_INVAL;
               n_pstate_ex_no = 1;
               break;
            }
         }
         if(n_is_dir(cp, FAL0)){
            n_err(_("%s: is a directory\n"), n_shexp_quote_cp(cp, FAL0));
            if(a_HARDERR())
               goto jerr;
            n_pstate_err_no = n_ERR_ISDIR;
            n_pstate_ex_no = 1;
            break;
         }
         if((n_pstate_err_no = a_coll_include_file(cp, (c == 'R'), TRU1)
               ) != n_ERR_NONE){
            if(ferror(_coll_fp))
               goto jerr;
            if(a_HARDERR())
               goto jerr;
            n_pstate_ex_no = 1;
            break;
         }
         n_pstate_err_no = n_ERR_NONE; /* XXX */
         n_pstate_ex_no = 0; /* XXX */
         break;
      case 'e':
      case 'v':
         /* Edit the current message.  'e' -> use EDITOR, 'v' -> use VISUAL */
         if(cnt != 0 || coap != NULL)
            goto jearg;
         rewind(_coll_fp);
         if((n_pstate_err_no = a_coll_edit(c, ok_blook(editheaders) ? hp : NULL)
               ) == n_ERR_NONE)
            n_pstate_ex_no = 0;
         else if(ferror(_coll_fp))
            goto jerr;
         else if(a_HARDERR())
            goto jerr;
         else
            n_pstate_ex_no = 1;
         goto jhistcont;
      case 'F':
      case 'f':
      case 'M':
      case 'm':
      case 'U':
      case 'u':
         /* Interpolate the named messages, if we are in receiving mail mode.
          * Does the standard list processing garbage.  If ~f is given, we
          * don't shift over */
         if((n_pstate_err_no = a_coll_forward(cp, _coll_fp, c)) == n_ERR_NONE)
            n_pstate_ex_no = 0;
         else if(ferror(_coll_fp))
            goto jerr;
         else if(a_HARDERR())
            goto jerr;
         else
            n_pstate_ex_no = 1;
         break;
      case 'H':
         /* Grab extra headers */
         if(cnt != 0)
            goto jearg;
         do
            grab_headers(n_GO_INPUT_CTX_COMPOSE, hp, GEXTRA, 0);
         while(check_from_and_sender(hp->h_from, hp->h_sender) == NULL);
         n_pstate_err_no = n_ERR_NONE; /* XXX */
         n_pstate_ex_no = 0; /* XXX */
         break;
      case 'h':
         /* Grab a bunch of headers */
         if(cnt != 0)
            goto jearg;
         do
            grab_headers(n_GO_INPUT_CTX_COMPOSE, hp,
              (GTO | GSUBJECT | GCC | GBCC),
              (ok_blook(bsdcompat) && ok_blook(bsdorder)));
         while(hp->h_to == NULL);
         n_pstate_err_no = n_ERR_NONE; /* XXX */
         n_pstate_ex_no = 0; /* XXX */
         break;
      case 'I':
      case 'i':
         /* Insert a variable into the file */
         if(cnt == 0)
            goto jearg;
         cp = n_var_vlook(cp, TRU1);
jIi_putesc:
         if(cp == NULL || *cp == '\0')
            break;
         if(!a_coll_putesc(cp, (c != 'I'), _coll_fp))
            goto jerr;
         if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT) &&
               !a_coll_putesc(cp, (c != 'I'), n_stdout))
            goto jerr;
         n_pstate_err_no = n_ERR_NONE; /* XXX */
         n_pstate_ex_no = 0; /* XXX */
         break;
      /* case 'M': <> 'F' */
      /* case 'm': <> 'f' */
      case 'p':
         /* Print current state of the message without altering anything */
         if(cnt != 0)
            goto jearg;
         print_collf(_coll_fp, hp); /* XXX pstate_err_no ++ */
         if(ferror(_coll_fp))
            goto jerr;
         n_pstate_err_no = n_ERR_NONE; /* XXX */
         n_pstate_ex_no = 0; /* XXX */
         break;
      case 'q':
      case 'x':
         /* Force a quit, act like an interrupt had happened */
         if(cnt != 0)
            goto jearg;
         /* If we are running a splice hook, assume it quits on its own now,
          * otherwise we (no true out-of-band IPC to signal this state, XXX sic)
          * have to SIGTERM it in order to stop this wild beast */
         flags |= a_COAP_NOSIGTERM;
         ++_coll_hadintr;
         _collint((c == 'x') ? 0 : SIGINT);
         exit(n_EXIT_ERR);
         /*NOTREACHED*/
      /* case 'R': <> 'd' */
      /* case 'r': <> 'd' */
      case 's':
         /* Set the Subject list */
         if(cnt == 0)
            goto jearg;
         /* Subject:; take care for Debian #419840 and strip any \r and \n */
         if(n_anyof_cp("\n\r", hp->h_subject = savestr(cp))){
            char *xp;

            n_err(_("-s: normalizing away invalid ASCII NL / CR bytes\n"));
            for(xp = hp->h_subject; *xp != '\0'; ++xp)
               if(*xp == '\n' || *xp == '\r')
                  *xp = ' ';
            n_pstate_err_no = n_ERR_INVAL;
            n_pstate_ex_no = 1;
         }else{
            n_pstate_err_no = n_ERR_NONE;
            n_pstate_ex_no = 0;
         }
         break;
      case 't':
         /* Add to the To: list TODO join 'b', 'c' */
         if(cnt == 0)
            goto jearg;
         else{
            struct name *np;
            si8_t soe;

            soe = 0;
            if((np = checkaddrs(lextract(cp, GTO | GFULL), EACM_NORMAL, &soe)
                  ) != NULL)
               hp->h_to = cat(hp->h_to, np);
            if(soe == 0){
               n_pstate_err_no = n_ERR_NONE;
               n_pstate_ex_no = 0;
            }else{
               n_pstate_ex_no = 1;
               n_pstate_err_no = (soe < 0) ? n_ERR_PERM : n_ERR_INVAL;
            }
         }
         hist &= ~a_HIST_GABBY;
         break;
      /* case 'U': <> 'F' */
      /* case 'u': <> 'f' */
      /* case 'v': <> 'e' */
      case 'w':
         /* Write the message on a file */
         if(cnt == 0)
            goto jearg;
         if((cp = fexpand(cp, FEXP_LOCAL | FEXP_NOPROTO)) == NULL){
            n_err(_("Write what file!?\n"));
            if(a_HARDERR())
               goto jerr;
            n_pstate_err_no = n_ERR_INVAL;
            n_pstate_ex_no = 1;
            break;
         }
         rewind(_coll_fp);
         if((n_pstate_err_no = a_coll_write(cp, _coll_fp, 1)) == n_ERR_NONE)
            n_pstate_ex_no = 0;
         else if(ferror(_coll_fp))
            goto jerr;
         else if(a_HARDERR())
            goto jerr;
         else
            n_pstate_ex_no = 1;
         break;
      /* case 'x': <> 'q' */
      }

      /* Finally place an entry in history as applicable */
      if(0){
jhistcont:
         c = '\1';
      }else
         c = '\0';
      if(hist & a_HIST_ADD){
         /* Do not add *escape* to the history in order to allow history search
          * to be handled generically in the MLE regardless of actual *escape*
          * settings etc. */
         n_tty_addhist(&n_string_cp(sp)[1], (n_GO_INPUT_CTX_COMPOSE |
            (hist & a_HIST_GABBY ? n_GO_INPUT_HIST_GABBY : n_GO_INPUT_NONE)));
      }
      if(c != '\0')
         goto jcont;
   }

jout:
   /* Do we have *on-compose-splice-shell*, or *on-compose-splice*?
    * TODO Usual f...ed up state of signals and terminal etc. */
   if(coap == NULL && (cp = ok_vlook(on_compose_splice_shell)) != NULL) Jocs:{
      union {int (*ptf)(void); char const *sh;} u;
      char const *cmd;

      /* Reset *escape* and more to their defaults.  On change update manual! */
      if(ifs_saved == NULL)
         ifs_saved = savestr(ok_vlook(ifs));
      escape = n_ESCAPE[0];
      ok_vclear(ifs);

      if(coapm != NULL){
         /* XXX Due Popen() fflush(NULL) in PTF mode, ensure nothing to flush */
         /*if(!n_real_seek(_coll_fp, 0, SEEK_END))
          *  goto jerr;*/
         u.ptf = &a_coll_ocs__mac;
         cmd = (char*)-1;
         a_coll_ocs__macname = cp = coapm;
      }else{
         u.sh = ok_vlook(SHELL);
         cmd = cp;
      }

      i = strlen(cp) +1;
      coap = n_lofi_alloc(n_VSTRUCT_SIZEOF(struct a_coll_ocs_arg, coa_cmd
            ) + i);
      coap->coa_pipe[0] = coap->coa_pipe[1] = -1;
      coap->coa_stdin = coap->coa_stdout = NULL;
      coap->coa_senderr = checkaddr_err;
      memcpy(coap->coa_cmd, cp, i);

      hold_all_sigs();
      coap->coa_opipe = safe_signal(SIGPIPE, SIG_IGN);
      coap->coa_oint = safe_signal(SIGINT, SIG_IGN);
      rele_all_sigs();

      if(pipe_cloexec(coap->coa_pipe) != -1 &&
            (coap->coa_stdin = Fdopen(coap->coa_pipe[0], "r", FAL0)) != NULL &&
            (coap->coa_stdout = Popen(cmd, "W", u.sh, NULL, coap->coa_pipe[1])
             ) != NULL){
         close(coap->coa_pipe[1]);
         coap->coa_pipe[1] = -1;

         temporary_compose_mode_hook_call(NULL, NULL, NULL);
         n_go_splice_hack(coap->coa_cmd, coap->coa_stdin, coap->coa_stdout,
            (n_psonce & ~(n_PSO_INTERACTIVE | n_PSO_TTYIN | n_PSO_TTYOUT)),
            &a_coll_ocs__finalize, &coap);
         /* Hook version protocol for ~^: update manual upon change! */
         fputs(a_COLL_PLUMBING_VERSION "\n", coap->coa_stdout);
#undef a_COLL_PLUMBING_VERSION
         goto jcont;
      }

      c = n_err_no;
      a_coll_ocs__finalize(coap);
      n_perr(_("Cannot invoke *on-compose-splice(-shell)?*"), c);
      goto jerr;
   }
   if(*checkaddr_err != 0){
      *checkaddr_err = 0;
      goto jerr;
   }
   if(coapm == NULL && (coapm = ok_vlook(on_compose_splice)) != NULL)
      goto Jocs;
   if(coap != NULL){
      ok_vset(ifs, ifs_saved);
      ifs_saved = NULL;
   }

   /* Final chance to edit headers, if not already above */
   if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT)){
      if(ok_blook(bsdcompat) || ok_blook(askatend)){
         enum gfield gf;

         gf = GNONE;
         if(ok_blook(askcc))
            gf |= GCC;
         if(ok_blook(askbcc))
            gf |= GBCC;
         if(gf != 0)
            grab_headers(n_GO_INPUT_CTX_COMPOSE, hp, gf, 1);
      }
      if(ok_blook(askattach))
         hp->h_attach = n_attachment_list_edit(hp->h_attach,
               n_GO_INPUT_CTX_COMPOSE);
   }

   /* Execute compose-leave */
   if((cp = ok_vlook(on_compose_leave)) != NULL){
      setup_from_and_sender(hp);
      temporary_compose_mode_hook_call(cp, &n_temporary_compose_hook_varset,
         hp);
   }

   /* Add automatic receivers */
   if ((cp = ok_vlook(autocc)) != NULL && *cp != '\0')
      hp->h_cc = cat(hp->h_cc, checkaddrs(lextract(cp, GCC |
            (ok_blook(fullnames) ? GFULL | GSKIN : GSKIN)),
            EACM_NORMAL, checkaddr_err));
   if ((cp = ok_vlook(autobcc)) != NULL && *cp != '\0')
      hp->h_bcc = cat(hp->h_bcc, checkaddrs(lextract(cp, GBCC |
            (ok_blook(fullnames) ? GFULL | GSKIN : GSKIN)),
            EACM_NORMAL, checkaddr_err));
   if (*checkaddr_err != 0)
      goto jerr;

   if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT) &&
         ok_blook(asksend)){
      bool_t b;

      ifs_saved = coapm = NULL;
      coap = NULL;

      fprintf(n_stdout, _("-------\nEnvelope contains:\n")); /* xxx SEARCH112 */
      puthead(TRU1, hp, n_stdout,
         GIDENT | GREF_IRT  | GSUBJECT | GTO | GCC | GBCC | GCOMMA,
         SEND_TODISP, CONV_NONE, NULL, NULL);

jreasksend:
      if(n_go_input(n_GO_INPUT_CTX_COMPOSE | n_GO_INPUT_NL_ESC,
            _("Send this message [yes/no, empty: recompose]? "),
            &linebuf, &linesize, NULL, NULL) < 0){
         if(!n_go_input_is_eof())
            goto jerr;
         cp = n_1;
      }

      if((b = n_boolify(linebuf, UIZ_MAX, TRUM1)) < FAL0)
         goto jreasksend;
      if(b == TRU2)
         goto jcont;
      if(!b)
         goto jerr;
   }

   /* TODO Cannot do since it may require turning this into a multipart one */
   if(n_poption & n_PO_Mm_FLAG)
      goto jskiptails;

   /* Place signature? */
   if((cp = ok_vlook(signature)) != NULL && *cp != '\0'){ /* TODO OBSOLETE */
      char const *cpq;

      n_OBSOLETE(_("please use *on-compose-{leave,splice}* and/or "
         "*message-inject-tail*, not *signature*"));

      if((cpq = fexpand(cp, FEXP_LOCAL | FEXP_NOPROTO)) == NULL){
         n_err(_("*signature* expands to invalid file: %s\n"),
            n_shexp_quote_cp(cp, FAL0));
         goto jerr;
      }
      cpq = n_shexp_quote_cp(cp = cpq, FAL0);

      if((sigfp = Fopen(cp, "r")) == NULL){
         n_err(_("Can't open *signature* %s: %s\n"),
            cpq, n_err_to_doc(n_err_no));
         goto jerr;
      }

      if(linebuf == NULL)
         linebuf = n_alloc(linesize = LINESIZE);
      c = '\0';
      while((i = fread(linebuf, sizeof *linebuf, linesize, n_UNVOLATILE(sigfp)))
            > 0){
         c = linebuf[i - 1];
         if(i != fwrite(linebuf, sizeof *linebuf, i, _coll_fp))
            goto jerr;
      }

      /* C99 */{
         FILE *x = n_UNVOLATILE(sigfp);
         int e = n_err_no, ise = ferror(x);

         sigfp = NULL;
         Fclose(x);

         if(ise){
            n_err(_("Errors while reading *signature* %s: %s\n"),
               cpq, n_err_to_doc(e));
            goto jerr;
         }
      }

      if(c != '\0' && c != '\n')
         putc('\n', _coll_fp);
   }

   {  char const *cp_obsolete = ok_vlook(NAIL_TAIL);

      if(cp_obsolete != NULL)
         n_OBSOLETE(_("please use *message-inject-tail*, not *NAIL_TAIL*"));

   if((cp = ok_vlook(message_inject_tail)) != NULL ||
         (cp = cp_obsolete) != NULL){
      if(!a_coll_putesc(cp, TRU1, _coll_fp))
         goto jerr;
      if((n_psonce & n_PSO_INTERACTIVE) && !(n_pstate & n_PS_ROBOT) &&
            !a_coll_putesc(cp, TRU1, n_stdout))
         goto jerr;
   }
   }

jskiptails:
   if(fflush(_coll_fp))
      goto jerr;
   rewind(_coll_fp);

jleave:
   if (linebuf != NULL)
      n_free(linebuf);
   sigprocmask(SIG_BLOCK, &nset, NULL);
   n_pstate &= ~n_PS_COMPOSE_MODE;
   safe_signal(SIGINT, _coll_saveint);
   safe_signal(SIGHUP, _coll_savehup);
   sigprocmask(SIG_SETMASK, &oset, NULL);
   NYD_LEAVE;
   return _coll_fp;

jerr:
   hold_all_sigs();

   if(coap != NULL && coap != (struct a_coll_ocs_arg*)-1){
      if(!(flags & a_COAP_NOSIGTERM))
         n_psignal(coap->coa_stdout, SIGTERM);
      n_go_splice_hack_remove_after_jump();
      coap = NULL;
   }
   if(ifs_saved != NULL){
      ok_vset(ifs, ifs_saved);
      ifs_saved = NULL;
   }
   if(sigfp != NULL){
      Fclose(n_UNVOLATILE(sigfp));
      sigfp = NULL;
   }
   if(_coll_fp != NULL){
      Fclose(_coll_fp);
      _coll_fp = NULL;
   }

   rele_all_sigs();

   assert(checkaddr_err != NULL);
   /* TODO We don't save in $DEAD upon error because msg not readily composed?
    * TODO But this no good, it should go ZOMBIE / DRAFT / POSTPONED or what! */
   if(*checkaddr_err != 0){
      if(*checkaddr_err == 111)
         n_err(_("Compose mode splice hook failure\n"));
      else
         n_err(_("Some addressees were classified as \"hard error\"\n"));
   }else if(_coll_hadintr == 0){
      *checkaddr_err = TRU1; /* TODO ugly: "sendout_error" now.. */
      n_err(_("Failed to prepare composed message\n"));
   }
   goto jleave;

#undef a_HARDERR
}

/* s-it-mode */