Convert-UUlib/uulib/uuscan.c

/*
 * This file is part of uudeview, the simple and friendly multi-part multi-
 * file uudecoder  program  (c) 1994-2001 by Frank Pilhofer. The author may
 * be contacted at fp@fpx.de
 *
 * 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.
 */

/*
 * These are very central functions of UUDeview. Here, we scan a file
 * and decide whether it contains encoded data or not. ScanPart() must
 * be called repeatedly on the same file until feof(file). Each time,
 * it returns information about the next part found within.
 */

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

#ifdef SYSTEM_WINDLL
#include <windows.h>
#endif
#ifdef SYSTEM_OS2
#include <os2.h>
#endif

#include <stdio.h>
#include <ctype.h>

#ifdef STDC_HEADERS
#include <stdlib.h>
#include <string.h>
#endif
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_MEMORY_H
#include <memory.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif

#include <uudeview.h>
#include <uuint.h>
#include <fptools.h>
#include <uustring.h>

char * uuscan_id = "$Id: uuscan.c,v 1.31 2001/06/06 19:21:52 fp Exp $";

/*
 * Header fields we recognize as such. See RFC822. We add "From ",
 * the usual marker for a beginning of a new message, and a couple
 * of usual MDA, News and MIME headers.
 * We make a distinction of MIME headers as we need the difference
 * to scan the bodies from partial multipart messages.
 */

static char *knownmsgheaders[] = {
  "From ", "Return-Path:", "Received:", "Reply-To:",
  "From:", "Sender:", "Resent-Reply-To:", "Resent-From:",
  "Resent-Sender:", "Date:", "Resent-Date:", "To:",
  "Resent-To:", "Cc:", "Bcc:", "Resent-bcc:",
  "Message-ID:", "Resent-Message-Id:", "In-Reply-To:",
  "References:", "Keywords:", "Subject:", "Comments:",
  
  "Delivery-Date:", "Posted-Date:", "Received-Date:",
  "Precedence:", 

  "Path:", "Newsgroups:", "Organization:", "Lines:",
  "NNTP-Posting-Host:",
  NULL
};

static char *knownmimeheaders[] = {
  "Mime-Version:",  "Content-Transfer-Encoding:",
  "Content-Type:", "Content-Disposition:", 
  "Content-Description:", "Content-Length:",
  NULL
};

/*
 * for MIME (plaintext) parts without filename
 */
int mimseqno;

/*
 * how many lines do we read when checking for headers
 */
#define WAITHEADER      10

/*
 * The stack for encapsulated Multipart messages
 */
#define MSMAXDEPTH      3

int       mssdepth = 0;
scanstate multistack[MSMAXDEPTH+1];

/*
 * The state and the local envelope
 */
headers   localenv;
scanstate sstate;

/*
 * mallocable areas
 */

char *uuscan_shlline;
char *uuscan_pvvalue;
char *uuscan_phtext;
char *uuscan_sdline;
char *uuscan_sdbhds1;
char *uuscan_sdbhds2;
char *uuscan_spline;

/*
 * Macro: print cancellation message in UUScanPart
 */

#define SPCANCEL()      {UUMessage(uuscan_id,__LINE__,UUMSG_NOTE,uustring(S_SCAN_CANCEL));*errcode=UURET_CANCEL;goto ScanPartEmergency;}

/*
 * Is line empty? A line is empty if it is composed of whitespace.
 */

static int
IsLineEmpty (char *data)
{
  if (data == NULL) return 0;
  while (*data && isspace (*data)) data++;
  return ((*data)?0:1);
}

/*
 * Scans a potentially folded header line from the input file. If
 * initial is non-NULL, it is the first line of the header, useful
 * if the calling function just coincidentally noticed that this is
 * a header.
 * RFC0822 does not specify a maximum length for headers, but we
 * truncate everything beyond an insane value of 1024 characters.
 */

static char *
ScanHeaderLine (FILE *datei, char *initial)
{
  char *ptr=uuscan_shlline;
  int llength, c;
  long curpos;
  int hadcr;

  if (initial) {
    _FP_strncpy (uuscan_shlline, initial, 1024);
  }
  else {
    /* read first line */
    if (feof (datei) || ferror (datei))
      return NULL;
    if (_FP_fgets (uuscan_shlline, 1023, datei) == NULL)
      return NULL;
    uuscan_shlline[1023] = '\0';
  }

  llength = strlen (uuscan_shlline);
  hadcr   = 0;

  /* strip whitespace at end */
  ptr = uuscan_shlline + llength;
  while (llength && isspace(*(ptr-1))) {
    if (*(ptr-1) == '\012' || *(ptr-1) == '\015')
      hadcr = 1;
    ptr--; llength--;
  }
  if (llength == 0) {
    uuscan_shlline[0] = '\0';
    return uuscan_shlline;
  }

  while (!feof (datei)) {
    c = fgetc (datei);
    if (feof (datei))
      break;

    /*
     * If the line didn't have a CR, it was longer than 256 characters
     * and is continued anyway.
     */

    if (hadcr==1 && c != ' ' && c != '\t') {
      /* no LWSP-char, header line does not continue */
      ungetc (c, datei);
      break;
    }
    while (!feof (datei) && (c == ' ' || c == '\t'))
      c = fgetc (datei);

    if (!feof (datei))
      ungetc (c, datei);        /* push back for fgets() */

    /* insert a single LWSP */
    if (hadcr==1 && llength < 1023) {
      *ptr++ = ' ';
      llength++;
    }
    *ptr = '\0'; /* make lint happier */

    if (feof (datei))
      break;

    /* read next line */
    curpos = ftell (datei);
    if (_FP_fgets (uugen_inbuffer, 255, datei) == NULL)
      break;
    uugen_inbuffer[255] = '\0';

    if (IsLineEmpty (uugen_inbuffer)) { /* oops */
      fseek (datei, curpos, SEEK_SET);
      break;
    }

    _FP_strncpy (ptr, uugen_inbuffer, 1024-llength);

    /*
     * see if line was terminated with CR. Otherwise, it continues ...
     */
    c = strlen (ptr);
    if (c>0 && (ptr[c-1] == '\012' || ptr[c-1] == '\015'))
      hadcr = 1;
    else
      hadcr = 0;

    /*
     * strip whitespace
     */

    ptr     += c;
    llength += c;
    while (llength && isspace(*(ptr-1))) {
      ptr--; llength--;
    }
  }
  *ptr = '\0';

  if (llength == 0)
    return NULL;

  return uuscan_shlline;
}

/*
 * Extract the value from a MIME attribute=value pair. This function
 * receives a pointer to the attribute.
 */
static char *
ParseValue (char *attribute)
{
  char *ptr=uuscan_pvvalue;
  int length=0;

  if (attribute == NULL)
    return NULL;

  while ((isalnum(*attribute) || *attribute=='_') && *attribute != '=')
    attribute++;

  while (isspace(*attribute))
    attribute++;

  if (*attribute == '=') {
    attribute++;
    while (isspace (*attribute))
      attribute++;
  }
  else
    return NULL;

  if (*attribute == '"') {
    /* quoted-string */
    attribute++;
    while (*attribute && *attribute != '"' && length < 255) {
      if (*attribute == '\\')
        *ptr++ = *++attribute;
      else
        *ptr++ = *attribute;
      attribute++;
      length++;
    }
    *ptr = '\0';
  }
  else {
    /* tspecials from RFC1521 */

    while (*attribute && !isspace (*attribute) &&
           *attribute != '(' && *attribute != ')' &&
           *attribute != '<' && *attribute != '>' &&
           *attribute != '@' && *attribute != ',' &&
           *attribute != ';' && *attribute != ':' &&
           *attribute != '\\' &&*attribute != '"' &&
           *attribute != '/' && *attribute != '[' &&
           *attribute != ']' && *attribute != '?' &&
           *attribute != '=' && length < 255)
      *ptr++ = *attribute++;

    *ptr = '\0';
  }
  return uuscan_pvvalue;
}

/*
 * Extract the information we need from header fields
 */

static headers *
ParseHeader (headers *theheaders, char *line)
{
  char **variable=NULL;
  char *value, *ptr, *thenew;
  int delimit, length;

  if (line == NULL)
    return theheaders;

  if (_FP_strnicmp (line, "From:", 5) == 0) {
    if (theheaders->from) return theheaders;
    variable = &theheaders->from;
    value    = line+5;
    delimit  = 0;
  }
  else if (_FP_strnicmp (line, "Subject:", 8) == 0) {
    if (theheaders->subject) return theheaders;
    variable = &theheaders->subject;
    value    = line+8;
    delimit  = 0;
  }
  else if (_FP_strnicmp (line, "To:", 3) == 0) {
    if (theheaders->rcpt) return theheaders;
    variable = &theheaders->rcpt;
    value    = line+3;
    delimit  = 0;
  }
  else if (_FP_strnicmp (line, "Date:", 5) == 0) {
    if (theheaders->date) return theheaders;
    variable = &theheaders->date;
    value    = line+5;
    delimit  = 0;
  }
  else if (_FP_strnicmp (line, "Mime-Version:", 13) == 0) {
    if (theheaders->mimevers) return theheaders;
    variable = &theheaders->mimevers;
    value    = line+13;
    delimit  = 0;
  }
  else if (_FP_strnicmp (line, "Content-Type:", 13) == 0) {
    if (theheaders->ctype) return theheaders;
    variable = &theheaders->ctype;
    value    = line+13;
    delimit  = ';';

    /* we can probably extract more information */
    if ((ptr = _FP_stristr (line, "boundary")) != NULL) {
      if ((thenew = ParseValue (ptr))) {
        if (theheaders->boundary) free (theheaders->boundary);
        theheaders->boundary = _FP_strdup (thenew);
      }
    }
    if ((ptr = _FP_stristr (line, "name")) != NULL) {
      if ((thenew = ParseValue (ptr))) {
        if (theheaders->fname) free (theheaders->fname);
        theheaders->fname = _FP_strdup (thenew);
      }
    }
    if ((ptr = _FP_stristr (line, "id")) != NULL) {
      if ((thenew = ParseValue (ptr))) {
        if (theheaders->mimeid) free (theheaders->mimeid);
        theheaders->mimeid = _FP_strdup (thenew);
      }
    }
    if ((ptr = _FP_stristr (line, "number")) != NULL) {
      if ((thenew = ParseValue (ptr))) {
        theheaders->partno = atoi (thenew);
      }
    }
    if ((ptr = _FP_stristr (line, "total")) != NULL) {
      if ((thenew = ParseValue (ptr))) {
        theheaders->numparts = atoi (thenew);
      }
    }
  }
  else if (_FP_strnicmp (line, "Content-Transfer-Encoding:", 26) == 0) {
    if (theheaders->ctenc) return theheaders;
    variable = &theheaders->ctenc;
    value    = line+26;
    delimit  = ';';
  }
  else if (_FP_strnicmp (line, "Content-Disposition:", 20) == 0) {
    /*
     * Some encoders mention the original filename as parameter to
     * Content-Type, others as parameter to Content-Disposition. We
     * do prefer the first solution, but accept this situation, too.
     * TODO: Read RFC1806
     */
    if ((ptr = _FP_stristr (line, "name")) != NULL) {
      if (theheaders->fname == NULL && (thenew=ParseValue(ptr)) != NULL) {
        theheaders->fname = _FP_strdup (thenew);
      }
    }
    variable = NULL;
  }
  else {
    /*
     * nothing interesting
     */
    variable = NULL;
  }

  /*
   * okay, so extract the actual data
   */
  if (variable) {
    length = 0;
    ptr = uuscan_phtext;

    while (isspace (*value))
      value++;
    while (*value && (delimit==0 || *value!=delimit) &&
           *value != '\012' && *value != '\015' && length < 255) {
      *ptr++ = *value++;
      length++;
    }
    while (length && isspace(*(ptr-1))) {
      ptr--; length--;
    }
    *ptr = '\0';

    if ((*variable = _FP_strdup (uuscan_phtext)) == NULL)
      return NULL;
  }

  return theheaders;
}

/*
 * is this a header line we know about?
 */

static int
IsKnownHeader (char *line)
{
  char **iter = knownmsgheaders;

  while (iter && *iter) {
    if (_FP_strnicmp (line, *iter, strlen (*iter)) == 0)
      return 1;
    iter++;
  }

  iter = knownmimeheaders;

  while (iter && *iter) {
    if (_FP_strnicmp (line, *iter, strlen (*iter)) == 0)
      return 2;
    iter++;
  }

  return 0;
}

/*
 * Scan a header
 */

int
UUScanHeader (FILE *datei, headers *envelope)
{
  char *ptr;

  while (!feof (datei)) {
    if ((ptr = ScanHeaderLine (datei, NULL)) == NULL)
      break;
    if (*ptr == '\0' || *ptr == '\012' || *ptr == '\015')
      break;
    ParseHeader (envelope, ptr);
  }
  return 0;
}

/*
 * Scan something for encoded data and fill the fileread* structure.
 * If boundary is non-NULL, we stop after having read it. If Check-
 * Headers != 0, we also stop after we've found uu_headercount recog-
 * nized header lines.
 * If we have a boundary, then we also don't accept Base64; MIME mails
 * really should handle this properly.
 * We return -1 if something went wrong, 0 if everything is normal,
 * 1 if we found a new header and 2 if we found a boundary.
 * In MIME message bodies (not multiparts), we also disable our reduced
 * MIME handling.
 */

static int
ScanData (FILE *datei, char *fname, int *errcode,
          char *boundary, int ismime, int checkheaders,
          fileread *result)
{
  char *line=uuscan_sdline, *bhds1=uuscan_sdbhds1, *bhds2=uuscan_sdbhds2;
  static char *ptr, *p2, *p3=NULL, *bhdsp, bhl;
  int isb64[10], isuue[10], isxxe[10], isbhx[10], iscnt;
  int cbb64, cbuue, cbxxe, cbbhx;
  int bhflag=0, vflag, haddh=0, hadct=0;
  int bhrpc=0, bhnf=0, c, hcount, lcount, blen;
  int encoding=0, dflag=0, ctline=42;
  int dontcare=0, hadnl=0;
  long preheaders, oldposition;
  size_t dcc, bhopc;

  *errcode = UURET_OK;
  (void) UUDecodeLine (NULL, NULL, 0);          /* init */
  bhdsp = bhds2;

  if (datei == NULL || feof (datei))
    return -1;

  result->startpos = ftell (datei);
  hcount = lcount  = 0;

  for (iscnt=0; iscnt<10; iscnt++) {
    isb64[iscnt] = isuue[iscnt] = isxxe[iscnt] = isbhx[iscnt] = 0;
  }

  iscnt = 0;

  if (boundary)
    blen = strlen (boundary);

  while (!feof (datei)) {
    oldposition = ftell (datei);
    if (_FP_fgets (line, 255, datei) == NULL)
      break;
    if (ferror (datei))
      break;

    line[255] = '\0'; /* For Safety of string functions */

    /*
     * Make Busy Polls
     */

    if (UUBUSYPOLL(ftell(datei),progress.fsize)) {
      UUMessage (uuscan_id, __LINE__, UUMSG_NOTE,
                 uustring (S_SCAN_CANCEL));
      *errcode = UURET_CANCEL;
      break;
    }

    if (IsLineEmpty (line)) { /* line empty? */
      hcount = 0;
      hadnl  = 1;
      continue;               /* then ignore */
    }

    if (checkheaders) {
      if (IsKnownHeader (line)) {
        (void) ScanHeaderLine (datei, line);

        if (hcount == 0) {
          preheaders = oldposition;
          lcount     = 0;
        }
        hcount++;
        lcount++;

        /*
         * check for the various restart counters
         */

        if ((hcount >= hlcount.restart) ||
            (hcount >= hlcount.afterdata && ismime == 0) ||
            (hcount >= hlcount.afterdata && result->uudet) ||
            (hcount >= hlcount.afternl   && result->uudet && hadnl)) {
          /*
           * Hey, a new header starts here
           */
          fseek (datei, preheaders, SEEK_SET);
          break;
        }
        /* continue; */
      }
      else if (lcount > WAITHEADER) {
        hcount = 0;
        lcount = 0;
        dontcare=0;
      }
      else if (hcount) {
        lcount++;
        dontcare=1;
      }
      else {
        dontcare=0;
      }
    }
    else {
      dontcare=0;
    }

    if (boundary != NULL && 
        line[0] == '-' && line[1] == '-' &&
        strncmp (line+2, boundary, blen) == 0) {
      fseek (datei, oldposition, SEEK_SET);
      break;
    }
    if (boundary != NULL && line[0] == 'C' && line[1] == 'o' &&
        _FP_strnicmp (line, "Content-Type:", 13) == 0) {
      ptr = ScanHeaderLine (datei, line);
      p2  = (ptr)?_FP_stristr(ptr,"boundary"):NULL;
      p3  = (p2)?ParseValue(p2):NULL;

      if (p3 && strcmp (p3, boundary) == 0) {
        fseek (datei, oldposition, SEEK_SET);
        break;
      }
      else {
        p3 = NULL;
      }
    }

    if (strncmp      (line, "begin ",       6) == 0 ||
        _FP_strnicmp (line, "<pre>begin ", 11) == 0) {
      if ((result->begin || result->end ||
           result->uudet == B64ENCODED ||
           result->uudet == BH_ENCODED) && !uu_more_mime) {
        fseek (datei, oldposition, SEEK_SET);
        break;
      }
      
      if (*line == '<')
        ptr = line + 10;
      else
        ptr = line + 5;

      while (*ptr == ' ') ptr++;
      while (isdigit (*ptr)) 
        result->mode = result->mode * 8 + *ptr++ - '0';
      while (*ptr == ' ') ptr++;

      /*
       * We may have picked up a filename from a uuenview-style header
       */
      _FP_free (result->filename);
      result->filename = _FP_strdup (ptr);
      result->begin    = 1;

      while (isspace (result->filename[strlen(result->filename)-1]))
        result->filename[strlen(result->filename)-1] = '\0';

      continue;
    }

    if ((strncmp (line, "end", 3) == 0) && result->uudet != BH_ENCODED) {
      if (result->uudet == B64ENCODED && result->begin)
        result->uudet = XX_ENCODED;

      if (result->uudet != B64ENCODED) {
        result->end = 1;
        if (dflag && encoding)
          result->uudet = encoding;
        continue;
      }
    }

    hadnl = 0;

    /*
     * Detect a UUDeview-Style header
     */

    if (_FP_strnicmp (line, "_=_ Part ", 9) == 0) {
      if (result->uudet) {
        fseek (datei, oldposition, SEEK_SET);
        break;
      }
      result->partno = atoi (line + 8);
      if ((ptr = _FP_stristr (line, "of file ")) != NULL) {
        ptr += 8;
        while (isspace (*ptr)) ptr++;
        p2 = ptr;
        while (isalnum(*p2) || 
               *p2 == '.' || *p2=='_' || *p2 == '-' ||
               *p2 == '!' || *p2=='@' || *p2 == '$')
          p2++;
        c = *p2; *p2 = '\0';
        if (p2 != ptr && result->filename == NULL)
          result->filename = _FP_strdup (ptr);
        else if (p2 - ptr > 5 && strchr (ptr, '.') != NULL) {
          /*
           * This file name looks good, too. Let's use it
           */
          _FP_free (result->filename);
          result->filename = _FP_strdup (ptr);
        }
        *p2 = c;
      }
    }

    /*
     * Some reduced MIME handling. Only use if boundary == NULL. Also
     * accept the "X-Orcl-Content-Type" used by some braindead program.
     */
    if (boundary == NULL && !ismime && !uu_more_mime) {
      if (_FP_strnicmp (line, "Content-Type", 12) == 0 ||
          _FP_strnicmp (line, "X-Orcl-Content-Type", 19) == 0) {
        /*
         * We use Content-Type to mark a new attachment and split the file.
         * However, we do not split if we haven't found anything encoded yet.
         */
        if (result->uudet) {
          fseek (datei, oldposition, SEEK_SET);
          break;
        }
        if ((ptr = strchr (line, ':')) != NULL) {
          ptr++;
          while (isspace (*ptr)) ptr++; p2 = ptr;
          while (!isspace (*p2) && *p2 != ';') p2++;
          c = *p2; *p2 = '\0';
          if (p2 != ptr) {
            _FP_free (result->mimetype);
            result->mimetype = _FP_strdup (ptr);
          }
          *p2 = c;
        }
        ctline=0;
        hadct=1;
      }
      if ((ptr = _FP_stristr (line, "number=")) && ctline<4) {
        ptr += 7; if (*ptr == '"') ptr++;
        result->partno = atoi (ptr);
      }
      if ((ptr = _FP_stristr (line, "total=")) && ctline<4) {
        ptr += 6; if (*ptr == '"') ptr++;
        result->maxpno = atoi (ptr);
      }
      if ((ptr = _FP_stristr (line, "name=")) && ctline<4) {
        ptr += 5;
        while (isspace (*ptr)) ptr++;
        if (*ptr == '"' && *(ptr+1) && (p2 = strchr (ptr+2, '"')) != NULL) {
          c = *p2; *p2 = '\0';
          _FP_free (result->filename);
          result->filename = _FP_strdup (ptr+1);
          *p2 = c;
        }
        else if (*ptr=='\''&&*(ptr+1)&&(p2 = strchr(ptr+2, '\'')) != NULL) {
          c = *p2; *p2 = '\0';
          _FP_free (result->filename);
          result->filename = _FP_strdup (ptr+1);
          *p2 = c;
        }
        else {
          p2 = ptr;
          while (isalnum(*p2) || 
                 *p2 == '.' || *p2=='_' || *p2 == '-' ||
                 *p2 == '!' || *p2=='@' || *p2 == '$')
            p2++;
          c = *p2; *p2 = '\0';
          if (p2 != ptr && result->filename == NULL)
            result->filename = _FP_strdup (ptr);
          else if (p2 - ptr > 5 && strchr (ptr, '.') != NULL) {
            /*
             * This file name looks good, too. Let's use it
             */
            _FP_free (result->filename);
            result->filename = _FP_strdup (ptr);
          }
          *p2 = c;
        }
      }
      if ((ptr = _FP_stristr (line, "id=")) && ctline<4) {
        p2 = ptr += 3;
        if (*p2 == '"') {
          p2 = strchr (++ptr, '"');
        }
        else {
          while (*p2 && isprint(*p2) && !isspace(*p2) && *p2 != ';')
            p2++;
        }
        if (p2 && *p2 && p2!=ptr) {
          c = *p2; *p2 = '\0';
          if (result->mimeid)
            _FP_free (result->mimeid);
          result->mimeid = _FP_strdup (ptr);
          *p2 = c;
        }
      }
      
      /* 
       * Handling for very short Base64 files.
       */
      if (uu_tinyb64 && !ismime && !uu_more_mime) {
        if (line[0] == '-' && line[1] == '-') {
          if (dflag && (encoding==B64ENCODED || result->uudet==B64ENCODED)) {
            if (encoding==B64ENCODED && result->uudet==0 && (haddh||hadct)) {
              result->uudet = encoding;
              encoding = dflag = 0;
            }
            haddh = 1;
            continue;
          }
          hadct = 0;
        }
      }
    } /* end of reduced MIME handling */

    /*
     * If we're in "freestyle" mode, have not encountered anything
     * interesting yet, and stumble upon something that looks like
     * a boundary, followed by a Content-* line, try to use it.
     */

    if (boundary == NULL && !ismime && !uu_more_mime && dflag <= 1 &&
        line[0] == '-' && line[1] == '-' && strlen(line+2)>10 &&
        (((ptr = _FP_strrstr (line+2, "--")) == NULL) ||
         *(ptr+2) != '\012' && *(ptr+2) != '\015') &&
        _FP_strstr (line+2, "_=_") != NULL) {
      if (_FP_fgets (line, 255, datei) == NULL) {
        break;
      }
      if (_FP_strnicmp (line, "Content-", 8) == 0) {
        /*
         * Okay, let's do it. This breaks out of ScanData. ScanPart will
         * recognize the boundary on the next call and use it.
         */
        fseek (datei, oldposition, SEEK_SET);
        break;
      }
    }

    /*
     * if we haven't yet found anything encoded, try to find something
     */

    if (!(result->uudet)) {
      /*
       * Netscape-Repair code is the same as in uunconc.c
       */

      if ((vflag = UUValidData (line, 0, &bhflag)) == 0 && !ismime)
        vflag = UURepairData (datei, line, 0, &bhflag);

      /*
       * Check data against all possible encodings
       */

      isb64[iscnt%10] = (UUValidData (line, B64ENCODED, &bhflag)==B64ENCODED);
      isuue[iscnt%10] = (UUValidData (line, UU_ENCODED, &bhflag)==UU_ENCODED);
      isxxe[iscnt%10] = (UUValidData (line, XX_ENCODED, &bhflag)==XX_ENCODED);
      isbhx[iscnt%10] = (UUValidData (line, BH_ENCODED, &bhflag)==BH_ENCODED);

      /*
       * If we've got a first valid encoded line, we get suspicious if
       * it's shorter than, say, 40 characters.
       */

      if (vflag == B64ENCODED &&
          (dflag == 0 || encoding != B64ENCODED) &&
          strlen (line) < 40 && !result->begin && !uu_tinyb64) {
        isb64[iscnt%10] = 0;
        vflag = 0;
      }

      if ((vflag == UU_ENCODED || vflag == XX_ENCODED) &&
              (dflag == 0 || encoding != vflag) &&
              strlen (line) < 40 && !result->begin) {
        isuue[iscnt%10] = isxxe[iscnt%10] = 0;
        vflag = 0;
      }

      iscnt++;

      /*
       * Ah, so we got an encoded line? How interesting!
       */

      if (vflag) {
        /*
         * For BinHex data, we can use the initial colon ':' as begin
         * and the terminating colon as ':'.
         * If (vflag && !bhflag), this is the last line,
         */
        if (vflag == BH_ENCODED) {
          if (line[0] == ':' && result->end) {
            fseek (datei, oldposition, SEEK_SET);
            break;
          }
          if (line[0] == ':')
            result->begin = 1;
          if (bhflag == 0) {
            result->uudet = BH_ENCODED;
            result->end   = 1;
          }
        }
        /*
         * For BinHex files, the file name is encoded in the first encoded
         * data bytes. We try to extract it here
         */
        if (vflag == BH_ENCODED && bhnf == 0 && result->filename == NULL) {
          if (bhdsp == bhds2 ||
              ((bhdsp-bhds2) <= (int) bhds2[0] &&
               (bhdsp-bhds2) <  256)) { 
            dcc = UUDecodeLine (line, bhds1, BH_ENCODED);
            UUbhdecomp (bhds1, bhdsp, &bhl, &bhrpc,
                        dcc, 256-(bhdsp-bhds2), &bhopc);
            bhdsp += bhopc;
          }
          if ((bhdsp-bhds2) > (int) bhds2[0] && bhds2[0]>0 &&
              result->filename==NULL) {
            memcpy (bhds1, bhds2+1, (int) bhds2[0]);
            bhds1[(int)bhds2[0]]='\0';
            result->filename = _FP_strdup (bhds1);
            bhnf             = 1;
          }
          else if (bhdsp-bhds2 >= 256 && bhds2[0]>0) {
            memcpy (bhds1, bhds2+1, 255);
            bhds1[255]       = '\0';
            result->filename = _FP_strdup (bhds1);
            bhnf             = 1;
          }
          else if (bhds2[0] <= 0)
            bhnf = 1;
        }

        /*
         * We accept an encoding if it has been true for four consecutive
         * lines. Check the is<enc> arrays to avoid mistaking one encoding
         * for the other. Uuencoded data is rather easily mistaken for
         * Base 64. If the data matches more than one encoding, we need to
         * scan further.
         */

        if (iscnt > 3) {
          cbb64 = (isb64[(iscnt-1)%10] && isb64[(iscnt-2)%10] &&
                   isb64[(iscnt-3)%10] && isb64[(iscnt-4)%10]);
          cbuue = (isuue[(iscnt-1)%10] && isuue[(iscnt-2)%10] &&
                   isuue[(iscnt-3)%10] && isuue[(iscnt-4)%10]);
          cbxxe = (isxxe[(iscnt-1)%10] && isxxe[(iscnt-2)%10] &&
                   isxxe[(iscnt-3)%10] && isxxe[(iscnt-4)%10]);
          cbbhx = (isbhx[(iscnt-1)%10] && isbhx[(iscnt-2)%10] &&
                   isbhx[(iscnt-3)%10] && isbhx[(iscnt-4)%10]);
        }
        else {
          cbb64 = cbuue = cbxxe = cbbhx = 0;
        }

        if (cbb64 && !cbuue && !cbxxe && !cbbhx) {
          result->uudet = B64ENCODED;
        }
        else if (!cbb64 && cbuue && !cbxxe && !cbbhx) {
          result->uudet = UU_ENCODED;
        }
        else if (!cbb64 && !cbuue && cbxxe && !cbbhx) {
          result->uudet = XX_ENCODED;
        }
        else if (!cbb64 && !cbuue && !cbxxe && cbbhx) {
          result->uudet = BH_ENCODED;
        }

        if (result->uudet) {
          encoding = dflag = 0;

          /*
           * If we're in fast mode, we're told we don't have to look
           * for anything below, so we can as well break out of every-
           * thing
           * We cannot fast-scan if we have a boundary to look after.
           */

          if (uu_fast_scanning && boundary == NULL)
            break;

          /*
           * Skip the encoded data. We simply wait for a boundary, for
           * a header or for an empty line. But we also try to pick up
           * an "end"
           */

          hcount = lcount = 0;

          while (!feof (datei)) {
            /*
             * Make Busy Polls
             */
            if (UUBUSYPOLL(ftell(datei),progress.fsize)) {
              UUMessage (uuscan_id, __LINE__, UUMSG_NOTE,
                         uustring (S_SCAN_CANCEL));
              *errcode = UURET_CANCEL;
              break;
            }

            oldposition = ftell (datei);
            if (_FP_fgets (line, 255, datei) == NULL)
              break;
            if (ferror (datei))
              break;

            line[255] = '\0';

            /*
             * Stop scanning at an empty line or a MIME-boundary.
             */
            if (IsLineEmpty (line))
              break;
            if (boundary && line[0] == '-' && line[1] == '-' &&
                strncmp (line+2, boundary, blen) == 0) {
              fseek (datei, oldposition, SEEK_SET);
              break;
            }
            else if (line[0] == 'e' && (result->uudet == UU_ENCODED ||
                                        result->uudet == XX_ENCODED)) {
              if (strncmp (line, "end", 3) == 0) {
                result->end = 1;
                break;
              }
            }
            else if (line[0] == 'b') {
              if (strncmp (line, "begin ", 6) == 0) {
                fseek (datei, oldposition, SEEK_SET);
                break;
              }
            }

            if (checkheaders) {
              if (IsKnownHeader (line)) {
                (void) ScanHeaderLine (datei, line);
                if (hcount == 0)
                  preheaders = oldposition;
                hcount++;
                lcount++;
                if ((hcount >= hlcount.restart) ||
                    (hcount >= hlcount.afterdata && result->uudet)) {
                  /*
                   * Hey, a new header starts here
                   */
                  fseek (datei, preheaders, SEEK_SET);
                  break;
                }
              }
              else if (lcount > WAITHEADER) {
                hcount = 0;
                lcount = 0;
              }
              else if (hcount) {
                lcount++;
              }
            }
            if (result->uudet == BH_ENCODED) {
              /* pick up ``EOF'' for BinHex files. Slow :-< */
              if (line[0] && strchr (line+1, ':') != NULL) {
                result->end = 1;
                bhflag      = 0;
                break;
              }
            }
          }

          if (ferror (datei) || *errcode == UURET_CANCEL)
            break;

          if (line[0] == '-' && line[1] == '-')
            haddh = 1;

          /*
           * Okay, got everything we need. If we had headers or a
           * boundary, we break out of the outer loop immediately.
           */

          if (IsKnownHeader (line) ||
              (boundary && line[0] == '-' && line[1] == '-' &&
               strncmp (line+2, boundary, blen) == 0)) {
            break;
          }

          /*
           * Otherwise, we wait until finding something more interesting
           * in the outer loop
           */

          continue;
        }
        
        /*
         * Select the encoding with the best "history"
         */

        cbb64 = isb64[(iscnt-1)%10];
        cbuue = isuue[(iscnt-1)%10];
        cbxxe = isxxe[(iscnt-1)%10];
        cbbhx = isbhx[(iscnt-1)%10];
        dflag = 0;

        if (cbb64 || cbuue || cbxxe || cbbhx) {
          for (dflag=2; dflag<iscnt && dflag<4; dflag++) {
            if ((!cbb64 || !isb64[(iscnt-dflag)%10]) &&
                (!cbuue || !isuue[(iscnt-dflag)%10]) &&
                (!cbxxe || !isxxe[(iscnt-dflag)%10]) &&
                (!cbbhx || !isbhx[(iscnt-dflag)%10])) {
              dflag--;
              break;
            }
            cbb64 &= isb64[(iscnt-dflag)%10];
            cbuue &= isuue[(iscnt-dflag)%10];
            cbxxe &= isxxe[(iscnt-dflag)%10];
            cbbhx &= isbhx[(iscnt-dflag)%10];
          }
        }

        /*
         * clear-cut cases
         */

        if (cbb64 && !cbuue && !cbxxe && !cbbhx) {
          encoding = B64ENCODED;
        }
        else if (!cbb64 && cbuue && !cbxxe && !cbbhx) {
          encoding = UU_ENCODED;
        }
        else if (!cbb64 && !cbuue && cbxxe && !cbbhx) {
          encoding = XX_ENCODED;
        }
        else if (!cbb64 && !cbuue && !cbxxe && cbbhx) {
          encoding = BH_ENCODED;
        }
        else {
          encoding = 0;
        }

        /*
         * Check a few common non-clear-cut cases
         */

        if (!encoding && cbuue && result->begin) {
          encoding = UU_ENCODED;
        }
        else if (!encoding && cbxxe && result->begin) {
          encoding = XX_ENCODED;
        }
        else if (!encoding && cbb64) {
          encoding = B64ENCODED;
        }
        else if (!encoding && cbuue) {
          encoding = UU_ENCODED;
        }
        else if (!encoding && cbxxe) {
          encoding = XX_ENCODED;
        }
        else if (!encoding && cbbhx) {
          encoding = BH_ENCODED;
        }
      }
      else if (!dontcare) {
        encoding = 0;
        dflag = 0;
        haddh = 0;
      }
    } /* if (!uudet) */
    /*
     * End of scanning loop
     */
  } /* while (!feof (datei)) */

  if (feof (datei))
    oldposition = ftell (datei);

  if (dflag && encoding == B64ENCODED && haddh)
    result->uudet = B64ENCODED;
  else if (dflag && encoding == BH_ENCODED)
    result->uudet = BH_ENCODED;

  /* Base64 doesn't have begin or end, so it was probably XX */
  if (result->uudet == B64ENCODED && result->begin && result->end)
    result->uudet = XX_ENCODED;

  /* Base64 doesn't have begin or end */
  if (result->uudet == B64ENCODED)
    result->begin = result->end = 0;

  /* Base64 and BinHex don't have a file mode */
  if (result->uudet == B64ENCODED || result->uudet == BH_ENCODED)
    result->mode  = 6*64+4*8+4;

  /*
   * When strict MIME adherance is set, throw out suspicious attachments
   */

  if (uu_more_mime) {
    /*
     * In a MIME message, Base64 should be appropriately tagged
     */

    if (result->uudet == B64ENCODED) {
      result->uudet = 0;
    }

    /*
     * Do not accept incomplete UU or XX encoded messages
     */

    if ((result->uudet != 0 && result->uudet != B64ENCODED) &&
        (!result->begin || !result->end)) {
      result->uudet = 0;
    }
  }

  /*
   * In fast mode, this length will yield a false value. We don't care.
   * This must be checked for in uunconc(), where we usually stop decoding
   * after reaching startpos+length
   */

  if (uu_fast_scanning)
    result->length = progress.fsize-result->startpos;
  else
    result->length = ftell(datei)-result->startpos;

  if (ferror (datei)) {
    *errcode = UURET_IOERR;
    uu_errno = errno;
    return -1;
  }
  if (*errcode != UURET_OK) {
    return -1;
  }

  if (boundary && line[0] == '-' && line[1] == '-' &&
      strncmp (line+2, boundary, blen) == 0)
    return 2;
  else if (boundary && p3 &&
           line[0] == 'C' && line[1] == 'o' &&
           _FP_strnicmp (line, "Content-Type:", 13) == 0 &&
           strcmp (p3, boundary) == 0)
    return 2;
  else if (IsKnownHeader (line))
    return 1;

  return 0;
}

/*
 * This is the main scanning function.
 */

fileread *
ScanPart (FILE *datei, char *fname, int *errcode)
{
  int ecount, hcount, lcount;
  int bhflag, begflag, vflag, blen, res;
  long preheaders, prevpos, preenc, before;
  char *line=uuscan_spline;
  fileread *result;
  char *ptr1, *ptr2;

  (void) UUDecodeLine (NULL, NULL, 0);          /* init */
  if (datei == NULL || feof (datei)) {
    *errcode = UURET_OK;
    return NULL;
  }

  *errcode = UURET_OK;

  if ((result = (fileread *) malloc (sizeof (fileread))) == NULL) {
    *errcode = UURET_NOMEM;
    return NULL;
  }
  memset (result, 0, sizeof (fileread));
  result->startpos = ftell (datei);
  preheaders       = result->startpos;
  before           = result->startpos;

  /* if this is a new file, reset our scanning state */
  if (sstate.source == NULL || strcmp (fname, sstate.source) != 0) {
    sstate.isfolder  = 1;               /* assume yes            */
    sstate.ismime    = 0;               /* wait for MIME-Version */
    sstate.mimestate = MS_HEADERS;      /* assume headers follow */
    /* mimseqno      = 1; */

    while (mssdepth) {
      mssdepth--;
      UUkillheaders (&(multistack[mssdepth].envelope));
      _FP_free (multistack[mssdepth].source);
    }

    UUkillheaders (&sstate.envelope);
    memset (&sstate.envelope, 0, sizeof (headers));

    _FP_free (sstate.source);
    if ((sstate.source = _FP_strdup (fname)) == NULL) {
      *errcode = UURET_NOMEM;
      _FP_free (result);
      return NULL;
    }

    /* ignore empty lines at the beginning of a file */
    preheaders = ftell (datei);
    while (!feof (datei)) {
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      if (_FP_fgets (line, 255, datei) == NULL)
        break;
      if (!IsLineEmpty (line)) {
        fseek (datei, preheaders, SEEK_SET);
        line[255] = '\0';
        break;
      }
      preheaders = ftell (datei);
    }
  }

  if (ferror(datei) || feof(datei)) {
    _FP_free (result);
    return NULL;
  }

  /*
   * If we are confident that this is a mail folder and are at the
   * beginning of the file, expecting to read some headers, scan
   * the envelope.
   */

  if (sstate.isfolder && sstate.mimestate == MS_HEADERS) {
    hcount = 0;
    lcount = 0;
    UUkillheaders (&sstate.envelope);

    /*
     * clean up leftovers from invalid messages
     */

    while (mssdepth) {
      mssdepth--;
      UUkillheaders (&(multistack[mssdepth].envelope));
      _FP_free (multistack[mssdepth].source);
    }

    if (_FP_fgets (line, 255, datei) == NULL) {
      _FP_free (result);
      return NULL;
    }
    line[255] = '\0';

    /*
     * Special handling for AOL folder files, which start off with a boundary.
     * We recognize them by a valid boundary line as the first line of a file.
     * Note that the rest of the scanning code becomes suspicious if a boun-
     * dary does never appear in a file -- this should save us from grave
     * false detection errors
     */

    if (!feof (datei) && line[0] == '-' && line[1] == '-' && line[2]) {
      while (line[strlen(line)-1] == '\012' ||
             line[strlen(line)-1] == '\015') {
        line[strlen(line)-1] = '\0';
      }

      sstate.ismime            = 1;
      sstate.envelope.mimevers = _FP_strdup ("1.0");
      sstate.envelope.boundary = _FP_strdup (line+2);
      sstate.envelope.ctype    = _FP_strdup ("multipart/mixed");
      sstate.mimestate         = MS_SUBPART;

      *errcode = UURET_CONT;
      _FP_free (result);
      return NULL;
    }

    /*
     * Normal behavior: look for a RFC 822 header
     */

    while (!feof (datei) && !IsLineEmpty (line)) {
      if (IsKnownHeader (line))
        hcount++;
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      ptr1 = ScanHeaderLine (datei, line);
      if (ParseHeader (&sstate.envelope, ptr1) == NULL) {
        *errcode = UURET_NOMEM;
        _FP_free (result);
        return NULL;
      }
      /*
       * if we've read too many lines without finding headers, then
       * this probably isn't a mail folder after all
       */
      lcount++;
      if (lcount > WAITHEADER && hcount < hlcount.afternl)
        break;

      if (_FP_fgets (line, 255, datei) == NULL)
        break;
      line[255] = '\0';
    }
    /* skip empty lines */
    prevpos = ftell (datei);
    while (!feof (datei)) {
      if (_FP_fgets (line, 255, datei) == NULL)
        break;
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      if (!IsLineEmpty (line)) {
        fseek (datei, prevpos, SEEK_SET);
        line[255] = '\0';
        break;
      }
      prevpos = ftell (datei);
    }
    /*
     * If we don't have all valid MIME headers yet, but the following
     * line is a MIME header, accept it anyway.
     */

    if (!uu_more_mime &&
        sstate.envelope.mimevers == NULL &&
        sstate.envelope.ctype    == NULL &&
        sstate.envelope.ctenc    == NULL &&
        IsKnownHeader (line)) {
      /*
       * see above
       */
      if (_FP_fgets (line, 255, datei) == NULL) {
        line[0] = '\012';
        line[1] = '\0';
      }
      line[255] = '\0';

      while (!feof (datei) && !IsLineEmpty (line)) {
        if (IsKnownHeader (line))
          hcount++;
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        ptr1 = ScanHeaderLine (datei, line);
        if (ParseHeader (&sstate.envelope, ptr1) == NULL) {
          *errcode = UURET_NOMEM;
          _FP_free (result);
          return NULL;
        }
        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        line[255] = '\0';
      }
      /* skip empty lines */
      prevpos = ftell (datei);
      while (!feof (datei)) {
        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        if (!IsLineEmpty (line)) {
          fseek (datei, prevpos, SEEK_SET);
          line[255] = '\0';
          break;
        }
        prevpos = ftell (datei);
      }
    }

    /*
     * A partial multipart message probably has only a Content-Type
     * header but nothing else. In this case, at least simulate a
     * MIME message
     * if mimevers is not set but there are other well-known MIME
     * headers, don't be too picky about it.
     */
    if (sstate.envelope.ctype && sstate.envelope.mimevers==NULL  &&
        _FP_stristr (sstate.envelope.ctype, "multipart") != NULL &&
        sstate.envelope.boundary != NULL) {
      sstate.envelope.mimevers = _FP_strdup ("1.0");
      hcount = hlcount.afternl;
    }
    else if (sstate.envelope.mimevers==NULL && sstate.envelope.ctype &&
             sstate.envelope.fname && sstate.envelope.ctenc) {
      sstate.envelope.mimevers = _FP_strdup ("1.0");
      hcount = hlcount.afternl;
    }

    if (hcount < hlcount.afternl) {
      /* not a folder after all */
      fseek (datei, preheaders, SEEK_SET);
      sstate.isfolder = 0;
      sstate.ismime   = 0;
    }
    else if (sstate.envelope.mimevers != NULL) {
      /* this is a MIME file. check the Content-Type */
      sstate.ismime = 1;
      if (_FP_stristr (sstate.envelope.ctype, "multipart") != NULL) {
        if (sstate.envelope.boundary == NULL) {
          UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                     uustring (S_MIME_NO_BOUNDARY));
          sstate.mimestate = MS_BODY;
          _FP_free (sstate.envelope.ctype);
          sstate.envelope.ctype = _FP_strdup ("text/plain");
        }
        else {
          sstate.mimestate = MS_PREAMBLE;
        }
      }
      else {
        sstate.mimestate = MS_BODY;     /* just a `simple' message */
      }
    }
  }

  if (feof (datei) || ferror (datei)) { /* oops */
    _FP_free (result);
    return NULL;
  }

  /*
   * Handle MIME stuff
   */

  /*
   * Read Preamble. This must be ended by a sstate.envelope.boundary line.
   * If uu_usepreamble is set, we produce a result from this one
   */

  if (sstate.ismime && sstate.mimestate == MS_PREAMBLE) {
    result->startpos = ftell (datei);   /* remember start of preamble */
    prevpos          = ftell (datei);
    preheaders       = ftell (datei);

    blen   = strlen (sstate.envelope.boundary);
    lcount = 0;
    
    while (!feof (datei)) {
      if (_FP_fgets (line, 255, datei) == NULL) {
        line[0] = '\0';
        break;
      }
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      if (line[0] == '-' && line[1] == '-' &&
          strncmp (line+2, sstate.envelope.boundary, blen) == 0)
        break;
      if (!IsLineEmpty (line))
        lcount++;

      prevpos = ftell (datei);
    }
    if (feof (datei) || ferror (datei)) {
      UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                 uustring (S_MIME_B_NOT_FOUND));
      /*
       * restart and try again; don't restart if uu_fast_scanning
       */
      sstate.isfolder  = 0;
      sstate.ismime    = 0;
      sstate.mimestate = MS_BODY;

      if (!uu_fast_scanning) {
        *errcode = UURET_CONT;
        fseek (datei, preheaders, SEEK_SET);
      }
      _FP_free (result);
      return NULL;
    }
    if (line[0] == '-' && line[1] == '-' &&
        strncmp (line+2, sstate.envelope.boundary, blen) == 0) {
      ptr1 = line + 2 + blen;
      if (*ptr1 == '-' && *(ptr1+1) == '-') {
        /* Empty Multipart Message. Duh. */
        sstate.mimestate = MS_EPILOGUE;
      }
      else {
        sstate.mimestate = MS_SUBPART;
      }
    }
    else { /* shouldn't happen */
      UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                 uustring (S_MIME_B_NOT_FOUND));
      /*
       * restart and try again; don't restart if uu_fast_scanning
       */
      sstate.isfolder  = 0;
      sstate.ismime    = 0;
      sstate.mimestate = MS_BODY;

      if (!uu_fast_scanning) {
        *errcode = UURET_CONT;
        fseek (datei, preheaders, SEEK_SET);
      }
      _FP_free (result);
      return NULL;
    }
    /* produce result if uu_usepreamble is set */
    if (uu_usepreamble && lcount) {
      sprintf (line, "%04d.txt", ++mimseqno);
      result->subject  = _FP_strdup (sstate.envelope.subject);
      result->filename = _FP_strdup (line);
      result->origin   = _FP_strdup (sstate.envelope.from);
      result->mimeid   = _FP_strdup (sstate.envelope.mimeid);
      result->mimetype = _FP_strdup ("text/plain");
      result->mode     = 0644;
      result->uudet    = PT_ENCODED;    /* plain text */
      result->sfname   = _FP_strdup (fname);
      result->flags    = FL_SINGLE | FL_PROPER;
      /* result->startpos set from above */
      result->length   = prevpos - result->startpos;
      result->partno   = 1;

      /* MIME message, let's continue */
      *errcode = UURET_CONT;

      if ((sstate.envelope.subject != NULL && result->subject == NULL) ||
          result->filename == NULL || result->sfname == NULL) {
        *errcode = UURET_NOMEM;
      }

      return result;
    }
    /* MIME message, let's continue */
    if (*errcode == UURET_OK)
      *errcode = UURET_CONT;

    /* otherwise, just return NULL */
    _FP_free (result);
    return NULL;
  }

  /*
   * Read Epilogue, the plain text after the last boundary.
   * This can either end with new headers from the next message of a
   * mail folder or with a `parent' boundary if we are inside an
   * encapsulated Multipart message. Oh yes, and of course the file
   * may also simply end :-)
   * Another possibility is that we might find plain encoded data
   * without encapsulating message. We're not _too_ flexible here,
   * we won't detect Base64, and require a proper `begin' line for
   * uuencoding and xxencoding
   * If uu_usepreamble is set, we produce a result from this one
   */

  if (sstate.ismime && sstate.mimestate == MS_EPILOGUE) {
    result->startpos = ftell (datei);   /* remember start of epilogue */
    prevpos          = ftell (datei);
    preheaders       = ftell (datei);
    preenc           = ftell (datei);
    hcount = lcount  = 0;
    ecount = bhflag  = 0;
    begflag = vflag  = 0;
    res = 0;

    /*
     * If we are in the outermost message and uu_fast_scanning, we
     * know (or assume) that no more messages will follow, so there's
     * no need to scan the rest.
     */
    if (uu_fast_scanning && mssdepth == 0) {
      /*
       * check if the epilogue is empty
       */
      while (!feof (datei) && !ferror (datei) && lcount<10 && res==0) {
        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        if (!IsLineEmpty (line))
          res++;
        lcount++;
      }
      if (uu_usepreamble && res) {
        sprintf (line, "%04d.txt", ++mimseqno);
        result->subject  = _FP_strdup (sstate.envelope.subject);
        result->filename = _FP_strdup (line);
        result->origin   = _FP_strdup (sstate.envelope.from);
        result->mimeid   = _FP_strdup (sstate.envelope.mimeid);
        result->mimetype = _FP_strdup ("text/plain");
        result->mode     = 0644;
        result->uudet    = PT_ENCODED;  /* plain text */
        result->sfname   = _FP_strdup (fname);
        result->flags    = FL_SINGLE | FL_PROPER | FL_TOEND;
        result->partno   = 1;
        /* result->startpos set from above */
        result->length   = progress.fsize - result->startpos;

        if ((sstate.envelope.subject != NULL && result->subject == NULL) ||
            result->filename == NULL || result->sfname == NULL) {
          *errcode = UURET_NOMEM;
        }

        return result;
      }
      _FP_free (result);
      return NULL;
    }

    if (mssdepth > 0)
      blen = strlen (multistack[mssdepth-1].envelope.boundary);

    while (!feof (datei)) {
      if (_FP_fgets (line, 255, datei) == NULL) {
        line[0] = '\0';
        break;
      }
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      line[255] = '\0';
      /* check for parent boundary */
      if (mssdepth > 0 && line[0] == '-' && line[1] == '-' &&
          strncmp (line+2,
                   multistack[mssdepth-1].envelope.boundary, blen) == 0)
        break;

      /* check for next headers only at outermost level */
      if (mssdepth == 0 && IsKnownHeader (line)) {
        (void) ScanHeaderLine (datei, line);
        if (hcount == 0) {
          preheaders = prevpos;
          lcount     = 0;
        }
        hcount++; 
        lcount++;

        if (hcount >= hlcount.restart) {
          /* okay, new headers */
          break;
        }
      }
      else if (lcount > WAITHEADER) {
        hcount = 0;
        lcount = 0;
      }
      else if (hcount) {
        lcount++;
      }
      else {
        hcount = lcount = 0;
      }

      /* check for begin and encoded data only at outermost level */
      if (mssdepth == 0 && !uu_more_mime) {
        if (strncmp      (line, "begin ",       6) == 0 ||
            _FP_strnicmp (line, "<pre>begin ", 11) == 0) {
          preenc  = prevpos;
          begflag = 1;
        }
        else if (strncmp (line, "end", 3) == 0 && begflag) {
          ecount = ELC_COUNT;
          break;
        }
        else if ((vflag = UUValidData (line, 0, &bhflag)) != 0) {
          if (vflag == BH_ENCODED && bhflag == 0) {
            /* very short BinHex file follows */
            preenc = prevpos;
            break;
          }
          /* remember that XX can easily be mistaken as Base64 */
          if ((vflag == UU_ENCODED || vflag == XX_ENCODED ||
               vflag == B64ENCODED) && begflag) {
            if (++ecount >= ELC_COUNT)
              break;
          }
          else {
            begflag = 0;
            ecount  = 0;
          }
        }
        else {
          begflag = 0;
          ecount  = 0;
        }
      }

      if (!IsLineEmpty (line))
        res++;

      prevpos = ftell (datei);
    }

    if (mssdepth > 0 && line[0] == '-' && line[1] == '-' &&
        strncmp (line+2,
                 multistack[mssdepth-1].envelope.boundary, blen) == 0) {
      /* restore previous state */
      mssdepth--;
      UUkillheaders (&sstate.envelope);
      _FP_free  (sstate.source);
      memcpy (&sstate, &(multistack[mssdepth]), sizeof (scanstate));

      ptr1 = line + 2 + strlen (sstate.envelope.boundary);

      if (*ptr1 == '-' && *(ptr1+1) == '-') {
        sstate.mimestate = MS_EPILOGUE;
      }
      else {
        sstate.mimestate = MS_SUBPART;
      }
      result->length = prevpos - result->startpos;
      *errcode = UURET_CONT;
    }
    else if (mssdepth > 0) {
      UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                 uustring (S_MIME_B_NOT_FOUND));
      /*
       * restart and try again; don't restart if uu_fast_scanning
       */
      sstate.isfolder  = 0;
      sstate.ismime    = 0;
      sstate.mimestate = MS_BODY;

      while (mssdepth) {
        mssdepth--;
        UUkillheaders (&(multistack[mssdepth].envelope));
        _FP_free (multistack[mssdepth].source);
      }

      if (!uu_fast_scanning) {
        *errcode = UURET_CONT;
        fseek (datei, preheaders, SEEK_SET);
      }
      _FP_free (result);
      return NULL;
    }
    else if (IsKnownHeader (line)) {
      /* new message follows */
      sstate.isfolder  = 1;
      sstate.ismime    = 0;
      sstate.mimestate = MS_HEADERS;
      result->length   = preheaders - result->startpos;
      fseek (datei, preheaders, SEEK_SET);
    }
    else if (ecount >= ELC_COUNT) {
      /* new plain encoding */
      sstate.isfolder  = 0;
      sstate.ismime    = 0;
      sstate.mimestate = MS_BODY;
      result->length   = preenc - result->startpos;
      fseek (datei, preenc, SEEK_SET);
    }

    /* produce result if uu_usepreamble is set */
    if (uu_usepreamble && res) {
      sprintf (line, "%04d.txt", ++mimseqno);
      result->subject  = _FP_strdup (sstate.envelope.subject);
      result->filename = _FP_strdup (line);
      result->origin   = _FP_strdup (sstate.envelope.from);
      result->mimeid   = _FP_strdup (sstate.envelope.mimeid);
      result->mimetype = _FP_strdup ("text/plain");
      result->mode     = 0644;
      result->uudet    = PT_ENCODED;    /* plain text */
      result->sfname   = _FP_strdup (fname);
      result->flags    = FL_SINGLE | FL_PROPER;
      result->partno   = 1;
      /* result->startpos set from above */
      /* result->length set from above */

      if ((sstate.envelope.subject != NULL && result->subject == NULL) ||
          result->filename == NULL || result->sfname == NULL) {
        *errcode = UURET_NOMEM;
      }

      return result;
    }
    /* otherwise, just return NULL */
    _FP_free (result);
    return NULL;
  }

  /*
   * Scan a new part from a Multipart message. Check for a new local
   * envelope (which defaults to `Content-Type: text/plain') and
   * evaluate its Content-Type and Content-Transfer-Encoding. If this
   * is another Multipart/something, push the current state onto our
   * stack and dive into the new environment, starting with another
   * preamble.
   */
                           
  if (sstate.ismime && sstate.mimestate == MS_SUBPART) {
    memset (&localenv, 0, sizeof (headers));
    result->startpos = ftell (datei);
    prevpos = ftell (datei);
    hcount  = 0;
    lcount  = 0;

    /*
     * Duplicate some data from outer envelope
     */

    localenv.mimevers = _FP_strdup (sstate.envelope.mimevers);
    localenv.from     = _FP_strdup (sstate.envelope.from);
    localenv.subject  = _FP_strdup (sstate.envelope.subject);
    localenv.rcpt     = _FP_strdup (sstate.envelope.rcpt);
    localenv.date     = _FP_strdup (sstate.envelope.date);

    if ((sstate.envelope.mimevers != NULL && localenv.mimevers == NULL) ||
        (sstate.envelope.from     != NULL && localenv.from     == NULL) ||
        (sstate.envelope.subject  != NULL && localenv.subject  == NULL) ||
        (sstate.envelope.rcpt     != NULL && localenv.rcpt     == NULL) ||
        (sstate.envelope.date     != NULL && localenv.date     == NULL)) {

      while (mssdepth) {
        mssdepth--;
        UUkillheaders (&(multistack[mssdepth].envelope));
        _FP_free (multistack[mssdepth].source);
      }
      sstate.isfolder = 0;
      sstate.ismime   = 0;
      
      UUkillheaders (&localenv);
      *errcode = UURET_NOMEM;
      _FP_free (result);
      return NULL;
    }
    
    /* Scan subheader. But what if there is no subheader? */
    hcount = 0;
    lcount = 0;
    preheaders = prevpos;
    
    if (_FP_fgets (line, 255, datei) == NULL) {
      sstate.isfolder = 0;
      sstate.ismime   = 0;
      while (mssdepth) {
        mssdepth--;
        UUkillheaders (&(multistack[mssdepth].envelope));
        _FP_free (multistack[mssdepth].source);
      }
      UUkillheaders (&localenv);
      _FP_free (result);
      return NULL;
    }
    line[255] = '\0';

    while (!feof (datei) && !IsLineEmpty (line)) {
      if (IsKnownHeader (line))
        hcount++;
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      if (lcount > WAITHEADER && hcount == 0) {
        fseek (datei, preheaders, SEEK_SET);
        prevpos = preheaders;
        break;
      }
      ptr1 = ScanHeaderLine (datei, line);
      if (ParseHeader (&localenv, ptr1) == NULL)
        *errcode = UURET_NOMEM;

      if (line[0] == '-' && line[1] == '-')
        break;

      prevpos = ftell (datei);

      if (_FP_fgets (line, 255, datei) == NULL)
        break;
      line[255] = '\0';
      lcount++;
    }
    if (line[0] == '-' && line[1] == '-') {
      /*
       * this shouldn't happen, there must always be an empty line,
       * but let's accept it anyway. Just skip back to before the
       * boundary, so that it gets handled below
       */
      fseek (datei, prevpos, SEEK_SET);
    }

    if (_FP_stristr (localenv.ctype, "multipart") != NULL) {
      /* oh no, not again */
      if (mssdepth >= MSMAXDEPTH) {
        /* Argh, what an isane message. Treat as plain text */
        UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                   uustring (S_MIME_MULTI_DEPTH));
      }
      else if (localenv.boundary == NULL) {
        UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                   uustring (S_MIME_NO_BOUNDARY));
      }
      else {
        memcpy (&multistack[mssdepth], &sstate, sizeof (scanstate));
        memcpy (&sstate.envelope,    &localenv, sizeof (headers));
        memset (&localenv, 0, sizeof (headers));
        sstate.mimestate = MS_PREAMBLE;
        if ((sstate.source = _FP_strdup (sstate.source)) == NULL)
          *errcode = UURET_NOMEM;

        if (*errcode == UURET_OK)
          *errcode = UURET_CONT;

        mssdepth++;
        /* need a restart */
        _FP_free (result);
        return NULL;
      }
    }
    /*
     * So this subpart is either plain text or something else. Check
     * the Content-Type and Content-Transfer-Encoding. If the latter
     * is a defined value, we know what to do and just copy everything
     * up to the boundary.
     * If Content-Transfer-Encoding is unknown or missing, look at the
     * Content-Type. If it's "text/plain" or undefined, we subject the
     * message to our encoding detection. Otherwise, treat as plain
     * text.
     * This is done because users might `attach' a uuencoded file, which
     * would then be correctly typed as `text/plain'.
     */
    if (_FP_stristr (localenv.ctenc, "base64") != NULL)
      result->uudet = B64ENCODED;
    else if (_FP_stristr (localenv.ctenc, "x-uue") != NULL)
      result->uudet = UU_ENCODED;
    else if (_FP_stristr (localenv.ctenc, "quoted-printable") != NULL)
      result->uudet = QP_ENCODED;
    else if (_FP_stristr (localenv.ctenc, "7bit") != NULL ||
             _FP_stristr (localenv.ctenc, "8bit") != NULL)
      result->uudet = PT_ENCODED;
    else if (_FP_stristr (localenv.ctype, "multipart") != NULL ||
             _FP_stristr (localenv.ctype, "message")   != NULL)
      result->uudet = PT_ENCODED;

    /*
     * If we're switched to MIME-only mode, handle as text
     */

    if (uu_more_mime >= 2 && !result->uudet) {
      result->uudet = PT_ENCODED;
    }

    if (result->uudet) {
      /*
       * Oh-kay, go ahead. Just read and wait for the boundary
       */
      result->startpos = ftell (datei);
      prevpos          = ftell (datei);
      blen = strlen (sstate.envelope.boundary);
      lcount = 0;
      
      while (!feof (datei)) {
        if (_FP_fgets (line, 255, datei) == NULL) {
          line[0] = '\0';
          break;
        }
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        line[255] = '\0';
        if (line[0] == '-' && line[1] == '-' &&
            strncmp (line+2, sstate.envelope.boundary, blen) == 0)
          break;
        /*
         * I've had a report of someone who tried to decode a huge file
         * that had an early truncated multipart message and later another
         * multipart message with the *same* boundary. Consequently, all
         * some hundred messages inbetween were ignored ...
         * This check here doesn't cover folded header lines, but we don't
         * want to slow down scanning too much. We just check for
         * Content-Type: multipart/... boundary="same-boundary"
         */
        if (line[0] == 'C' && line[1] == 'o' &&
            _FP_strnicmp (line, "Content-Type:", 13) == 0) {
          ptr1 = ScanHeaderLine (datei, line);
          ptr2 = (ptr1)?_FP_stristr(ptr1,"boundary"):NULL;
          ptr1 = (ptr2)?ParseValue(ptr2):NULL;
          if (ptr1 && strcmp (ptr1, sstate.envelope.boundary) == 0)
            break;
          for (res=0; ptr1 && res<mssdepth; res++)
            if (strcmp (ptr1, multistack[res].envelope.boundary) == 0)
              break;
          if (res<mssdepth)
            break;
        }
        if (!IsLineEmpty (line))
          lcount++;
        prevpos = ftell (datei);
      }
      if (line[0] == '-' && line[1] == '-' &&
          strncmp (line+2, sstate.envelope.boundary, blen) == 0) {
        ptr1 = line + 2 + blen;
        if (*ptr1 == '-' && *(ptr1+1) == '-')
          sstate.mimestate = MS_EPILOGUE;
        else
          sstate.mimestate = MS_SUBPART;
      }
      else {
        UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                   uustring (S_MIME_B_NOT_FOUND));

        while (mssdepth) {
          mssdepth--;
          UUkillheaders (&(multistack[mssdepth].envelope));
          _FP_free (multistack[mssdepth].source);
        }
        /*
         * Don't retry if uu_fast_scanning
         */

        if (uu_fast_scanning) {
          UUkillheaders (&localenv);
          sstate.isfolder  = 0;
          sstate.ismime    = 0;
          sstate.mimestate = MS_BODY;
          _FP_free (result);
          return NULL;
        }

        /*
         * Retry, but listening to headers this time
         */
        fseek (datei, result->startpos, SEEK_SET);

        UUkillfread (result);
        if ((result = (fileread *) malloc (sizeof (fileread))) == NULL) {
          *errcode = UURET_NOMEM;
          sstate.isfolder = 0;
          sstate.ismime   = 0;
          UUkillheaders (&localenv);
          return NULL;
        }
        memset (result, 0, sizeof (fileread));

        if ((res = ScanData (datei, fname, errcode, NULL, 1, 1, result))==-1) {
          /* oops, something went wrong */
          sstate.isfolder = 0;
          sstate.ismime   = 0;
          UUkillfread   (result);
          UUkillheaders (&localenv);
          return NULL;
        }
        if (res == 1) {
          /*
           * new headers found
           */
          sstate.isfolder  = 1;
          sstate.ismime    = 0;
          sstate.mimestate = MS_HEADERS;
        }
        else {
          sstate.isfolder  = 0;
          sstate.ismime    = 0;
        }
      }
      /* produce result if uu_handletext is set */
      /* or if the file is explicitely named */
      if (result->uudet == B64ENCODED || lcount) {
        if (localenv.fname) {
          _FP_free (result->filename);
          if ((result->filename = _FP_strdup (localenv.fname)) == NULL)
            *errcode = UURET_NOMEM;
        }
        else if ((result->uudet==QP_ENCODED||result->uudet==PT_ENCODED) &&
                 result->filename == NULL && uu_handletext) {
          sprintf (line, "%04d.txt", ++mimseqno);
          if ((result->filename = _FP_strdup (line)) == NULL)
            *errcode = UURET_NOMEM;
        }
        result->subject  = _FP_strdup (localenv.subject);
        result->origin   = _FP_strdup (localenv.from);
        result->mimeid   = _FP_strdup (localenv.mimeid);
        result->mimetype = _FP_strdup (localenv.ctype);
        result->mode     = 0644;
        result->sfname   = _FP_strdup (fname);
        result->flags    = FL_SINGLE | FL_PROPER;
        result->partno   = 1;
        /* result->uudet determined above */
        /* result->startpos set from above */
        result->length   = prevpos - result->startpos;

        if ((localenv.subject != NULL && result->subject == NULL) ||
            result->filename == NULL  || result->sfname == NULL) {
          *errcode = UURET_NOMEM;
        }
      }
      else {
        /* don't produce a result */
        _FP_free (result);
        result = NULL;
      }
      if (*errcode == UURET_OK)
        *errcode = UURET_CONT;
      /*
       * destroy local envelope
       */
      UUkillheaders (&localenv);
      return result;
    }

    /*
     * we're in a subpart, but the local headers don't give us any
     * clue about what's to find here. So look for encoded data by
     * ourselves.
     */

    if ((res = ScanData (datei, fname, errcode,
                         sstate.envelope.boundary,
                         1, 0, result)) == -1) {
      /* oops, something went wrong */
      sstate.isfolder = 0;
      sstate.ismime   = 0;
      UUkillfread   (result);
      UUkillheaders (&localenv);
      return NULL;
    }
    /*
     * we should really be at a boundary here, but check again
     */
    blen    = strlen (sstate.envelope.boundary);
    prevpos = ftell  (datei);

    while (!feof (datei)) {
      if (_FP_fgets (line, 255, datei) == NULL) {
        line[0] = '\0';
        break;
      }
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      line[255] = '\0';
      if (line[0] == '-' && line[1] == '-' &&
          strncmp (line+2, sstate.envelope.boundary, blen) == 0)
        break;
      if (line[0] == 'C' && line[1] == 'o' &&
          _FP_strnicmp (line, "Content-Type:", 13) == 0) {
        ptr1 = ScanHeaderLine (datei, line);
        ptr2 = (ptr1)?_FP_stristr(ptr1,"boundary"):NULL;
        ptr1 = (ptr2)?ParseValue(ptr2):NULL;
        if (ptr1 && strcmp (ptr1, sstate.envelope.boundary) == 0)
          break;
      }
      prevpos = ftell (datei);
    }
    /*
     * check if this was the last subpart
     */
    if (line[0] == '-' && line[1] == '-' &&
        strncmp (line+2, sstate.envelope.boundary, blen) == 0) {
      ptr1 = line + 2 + blen;
      if (*ptr1 == '-' && *(ptr1+1) == '-')
        sstate.mimestate = MS_EPILOGUE;
      else
        sstate.mimestate = MS_SUBPART;
    }
    else {
      UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                 uustring (S_MIME_B_NOT_FOUND));
      
      while (mssdepth) {
        mssdepth--;
        UUkillheaders (&(multistack[mssdepth].envelope));
        _FP_free (multistack[mssdepth].source);
      }

      if (uu_fast_scanning) {
        UUkillheaders (&localenv);
        sstate.isfolder  = 0;
        sstate.ismime    = 0;
        sstate.mimestate = MS_BODY;
        _FP_free (result);
        return NULL;
      }

      /*
       * Retry, listening to headers this time
       */
      fseek (datei, result->startpos, SEEK_SET);
      
      UUkillfread (result);
      if ((result = (fileread *) malloc (sizeof (fileread))) == NULL) {
        *errcode = UURET_NOMEM;
        sstate.isfolder = 0;
        sstate.ismime   = 0;
        UUkillheaders (&localenv);
        return NULL;
      }
      memset (result, 0, sizeof (fileread));

      if ((res = ScanData (datei, fname, errcode, NULL, 1, 1, result))==-1) {
        /* oops, something went wrong */
        sstate.isfolder = 0;
        sstate.ismime   = 0;
        UUkillfread   (result);
        UUkillheaders (&localenv);
        return NULL;
      }
      if (res == 1) {
        /*
         * new headers found
         */
        sstate.isfolder  = 1;
        sstate.ismime    = 0;
        sstate.mimestate = MS_HEADERS;
      }
      else {
        sstate.isfolder  = 0;
        sstate.ismime    = 0;
      }
    }

    /*
     * If this file has been nicely MIME so far, then be very suspicious
     * if ScanData reports anything else. So do a double check, and if
     * it doesn't hold up, handle as plain text instead.
     */

    if (strcmp (localenv.mimevers, "1.0") == 0 &&
        _FP_stristr (localenv.ctype, "text") != NULL &&
        sstate.ismime && sstate.mimestate == MS_SUBPART &&
        !uu_desperate) {
      if (result->uudet == UU_ENCODED && !(result->begin || result->end)) {
        result->uudet = 0;
      }
    }

    /*
     * produce result
     */

    if (result->uudet == 0) {
      result->uudet = PT_ENCODED; /* plain text */
    }

    if (localenv.fname) {
      _FP_free (result->filename);
      if ((result->filename = _FP_strdup (localenv.fname)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else if ((result->uudet==QP_ENCODED || result->uudet==PT_ENCODED) &&
             result->filename==NULL && uu_handletext) {
      sprintf (line, "%04d.txt", ++mimseqno);
      if ((result->filename = _FP_strdup (line)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else {
      /* assign a filename lateron */
    }
    if (result->mimetype) _FP_free (result->mimetype);
    if (result->uudet) {
      if (_FP_stristr (localenv.ctype, "text") != NULL &&
          result->uudet != QP_ENCODED && result->uudet != PT_ENCODED)
        result->mimetype = NULL; /* better don't set it */
      else
        result->mimetype = _FP_strdup (localenv.ctype);
    }
    if (result->origin) _FP_free  (result->origin);
    result->origin  = _FP_strdup  (localenv.from);

    if (result->subject) _FP_free (result->subject);
    result->subject = _FP_strdup  (localenv.subject);

    if (result->sfname == NULL)
      if ((result->sfname = _FP_strdup (fname)) == NULL)
        *errcode = UURET_NOMEM;

    result->length = prevpos - result->startpos;
    result->flags  = FL_SINGLE | FL_PROPER;
    result->partno = 1;

    if (result->mode == 0)
      result->mode = 0644;

    /*
     * the other fields should already be set appropriately
     */

    if (*errcode == UURET_OK)
      *errcode = UURET_CONT;

    /*
     * kill local envelope
     */
    UUkillheaders (&localenv);
    
    return result;
  }

  /*
   * All right, so we're not in a Multipart message. Phew, took quite
   * long to figure this out. But this might still be a MIME message
   * body. And if it's a message/partial, we need more special handling
   */

  if (sstate.isfolder && sstate.ismime && sstate.mimestate == MS_BODY &&
      _FP_stristr (sstate.envelope.ctype, "message") != NULL &&
      _FP_stristr (sstate.envelope.ctype, "partial") != NULL) {

    result->startpos = ftell (datei);

    if (sstate.envelope.partno == 1) {
      /* read local envelope */
      UUkillheaders (&localenv);
      memset (&localenv, 0, sizeof (headers));

      /* skip over blank lines first */
      prevpos = ftell (datei);
      while (!feof (datei)) {
        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        line[255] = '\0';
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        if (!IsLineEmpty (line))
          break;
        prevpos = ftell (datei);
      }
      /* Next, read header. But what if there is no subheader? */
      hcount = 0;
      lcount = 0;
      preheaders = prevpos;

      while (!feof (datei) && !IsLineEmpty (line)) {
        if (IsKnownHeader (line))
          hcount++;
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        if (lcount > WAITHEADER && hcount == 0) {
          fseek (datei, preheaders, SEEK_SET);
          break;
        }
        ptr1 = ScanHeaderLine (datei, line);
        if (ParseHeader (&localenv, ptr1) == NULL)
          *errcode = UURET_NOMEM;

        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        line[255] = '\0';
        lcount++;
      }
      prevpos = ftell (datei);
      /*
       * Examine local header. We're mostly interested in the Content-Type
       * and the Content-Transfer-Encoding.
       */
      if (_FP_stristr (localenv.ctype, "multipart") != NULL) {
        UUMessage (uuscan_id, __LINE__, UUMSG_WARNING,
                   uustring (S_MIME_PART_MULTI));
      }
      if (localenv.subject)
        result->subject  = _FP_strdup (localenv.subject);
      else
        result->subject  = _FP_strdup (sstate.envelope.subject);

      if (localenv.from)
        result->origin   = _FP_strdup (localenv.from);
      else
        result->origin   = _FP_strdup (sstate.envelope.from);

      if (localenv.ctype)
        result->mimetype = _FP_strdup (localenv.ctype);
      else
        result->mimetype = _FP_strdup ("text/plain");

      if (_FP_stristr (localenv.ctenc, "quoted-printable") != NULL)
        result->uudet = QP_ENCODED;
      else if (_FP_stristr (localenv.ctenc, "base64") != NULL)
        result->uudet = B64ENCODED;
      else if (_FP_stristr (localenv.ctenc, "x-uue") != NULL)
        result->uudet = UU_ENCODED;
      else if (_FP_stristr (localenv.ctenc, "7bit") != NULL ||
               _FP_stristr (localenv.ctenc, "8bit") != NULL)
        result->uudet = PT_ENCODED;
      else if (_FP_stristr (localenv.ctype, "multipart") != NULL ||
               _FP_stristr (localenv.ctype, "message")   != NULL)
        result->uudet = PT_ENCODED;

      /*
       * If we're switched to MIME-only mode, handle as text
       */

      if (uu_more_mime >= 2 && !result->uudet) {
        result->uudet = PT_ENCODED;
      }
    }
    else {
      memset (&localenv, 0, sizeof (headers));
    }

    /*
     * If this is Quoted-Printable or Plain Text, just try looking
     * for the next message header. If uu_fast_scanning, and the
     * encoding is known, there's no need to look below. Otherwise,
     * we check the type of encoding first.
     * The encoding type is determined on the first part; in all
     * others, we also don't read on.
     * If we have a partial multipart message, scan for headers, but
     * do not react on standard MIME headers, as they are probably
     * from the subparts. However, we're stuck if there's an embedded
     * message/rfc822 :-(
     * If it is a "trivial" (non-embedded) message/rfc822, skip over
     * the message header and then start looking for the next header.
     */
    if (uu_fast_scanning && (result->uudet!=0||sstate.envelope.partno!=1)) {
      /* do nothing */
      res = 0;
    }
    else if (result->uudet != 0) {
      hcount = lcount = 0;
      prevpos = ftell (datei);

      if (_FP_stristr (localenv.ctype, "message") != NULL &&
          _FP_stristr (localenv.ctype, "rfc822")  != NULL) {
        /*
         * skip over empty lines and local header
         */
        preheaders = ftell (datei);
        while (!feof (datei)) {
          if (_FP_fgets (line, 255, datei) == NULL)
            break;
          line[255] = '\0';
          if (!IsLineEmpty (line)) {
            break;
          }
        }

        while (!feof (datei) && !IsLineEmpty (line)) { 
          if (IsKnownHeader (line))
            hcount++;
          lcount++;
          if (lcount > WAITHEADER && hcount < hlcount.afternl)
            break;

          if (_FP_fgets (line, 255, datei) == NULL)
            break;
          line[255] = '\0';
        }
        if (hcount < hlcount.afternl)
          fseek (datei, preheaders, SEEK_SET);
        hcount = lcount = 0;
      }

      /*
       * look for next header
       */

      while (!feof (datei)) {
        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        if (ferror (datei))
          break;
        line[255] = '\0';

        if ((vflag = IsKnownHeader (line))) {
          (void) ScanHeaderLine (datei, line);

          if (result->uudet != PT_ENCODED || vflag == 1) {
            if (hcount == 0)
              preheaders = prevpos;
            hcount++;
            lcount++;
            if (hcount >= hlcount.restart) {
              /*
               * Hey, a new header starts here
               */
              fseek (datei, preheaders, SEEK_SET);
              prevpos = preheaders;
              break;
            }
          }
        }
        else if (lcount > WAITHEADER) {
          hcount = 0;
          lcount = 0;
        }
        else if (hcount) {
          lcount++;
        }
        prevpos = ftell (datei);
      }
      res = 1;
    }
    else {
      /*
       * Otherwise, let's see what we can find ourself. No
       * boundary (NULL) but MIME, and respect new headers.
       */
      if ((res = ScanData (datei, fname, errcode, NULL, 1, 1, result)) == -1) {
        /* oops, something went wrong */
        sstate.isfolder = 0;
        sstate.ismime   = 0;
        UUkillfread   (result);
        UUkillheaders (&localenv);
        return NULL;
      }
      if (result->uudet == 0 && uu_handletext)
        result->uudet = PT_ENCODED;

      prevpos = ftell (datei);
    }
    /*
     * produce result
     */
    if (localenv.fname) {
      _FP_free (result->filename);
      if ((result->filename = _FP_strdup (localenv.fname)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else if (sstate.envelope.fname) {
      _FP_free (result->filename);
      if ((result->filename = _FP_strdup (sstate.envelope.fname)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else if ((result->uudet==QP_ENCODED || result->uudet==PT_ENCODED) &&
             result->filename == NULL) {
      sprintf (line, "%04d.txt", ++mimseqno);
      if ((result->filename = _FP_strdup (line)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else {
      /* assign a filename lateron */
    }
    if (result->subject == NULL) {
      if (sstate.envelope.subject)
        result->subject = _FP_strdup (sstate.envelope.subject);
    }
    result->partno = sstate.envelope.partno;
    result->maxpno = sstate.envelope.numparts;
    result->flags  = FL_PARTIAL | 
      ((res==1 || uu_fast_scanning) ? FL_PROPER : 0) |
        ((uu_fast_scanning) ? FL_TOEND : 0);
    result->mimeid = _FP_strdup (sstate.envelope.mimeid);

    if (uu_fast_scanning)
      result->length = progress.fsize - result->startpos;
    else
      result->length = prevpos - result->startpos;

    if (result->sfname == NULL)
      result->sfname = _FP_strdup (fname);

    if (result->mode == 0)
      result->mode = 0644;

    /*
     * the other fields should already be set appropriately
     */

    if (res == 1) {
      /*
       * new headers found
       */
      sstate.isfolder  = 1;
      sstate.ismime    = 0;
      sstate.mimestate = MS_HEADERS;
      
      UUkillheaders (&sstate.envelope);
      memset (&sstate.envelope, 0, sizeof (headers));
    }
    else {
      /*
       * otherwise, this can't be a mail folder
       */
      sstate.isfolder  = 0;
      sstate.ismime    = 0;
    }
    /*
     * kill local envelope
     */
    UUkillheaders (&localenv);
    return result;
  }

  /*
   * If this is a MIME body, honor a Content-Type different than
   * text/plain or a proper Content-Transfer-Encoding.
   * We also go in here if we have an assigned filename - this means
   * that we've had a Content-Disposition field, and we should probably
   * decode a plain-text segment with a filename.
   */
  if (sstate.isfolder && sstate.ismime &&
      sstate.mimestate == MS_BODY &&
      (_FP_stristr (sstate.envelope.ctenc, "quoted-printable") != NULL ||
       _FP_stristr (sstate.envelope.ctenc, "base64")           != NULL ||
       _FP_stristr (sstate.envelope.ctenc, "x-uue")            != NULL ||
       _FP_stristr (sstate.envelope.ctype, "message")          != NULL ||
       sstate.envelope.fname != NULL)) {

    if (sstate.envelope.subject)
      result->subject = _FP_strdup (sstate.envelope.subject);
    if (sstate.envelope.from)
      result->origin  = _FP_strdup (sstate.envelope.from);

    if (sstate.envelope.ctype)
      result->mimetype = _FP_strdup (sstate.envelope.ctype);
    else
      result->mimetype = _FP_strdup ("text/plain");

    if (_FP_stristr (sstate.envelope.ctenc, "quoted-printable") != NULL)
      result->uudet = QP_ENCODED;
    else if (_FP_stristr (sstate.envelope.ctenc, "base64") != NULL)
      result->uudet = B64ENCODED;
    else if (_FP_stristr (sstate.envelope.ctenc, "x-uue") != NULL)
      result->uudet = UU_ENCODED;
    else if (_FP_stristr (sstate.envelope.ctenc, "7bit") != NULL ||
             _FP_stristr (sstate.envelope.ctenc, "8bit") != NULL)
      result->uudet = PT_ENCODED;
    else if (_FP_stristr (sstate.envelope.ctype, "multipart") != NULL ||
             _FP_stristr (sstate.envelope.ctype, "message")   != NULL ||
             sstate.envelope.fname != NULL)
      result->uudet = PT_ENCODED;

    /*
     * If we're switched to MIME-only mode, handle as text
     */

    if (uu_more_mime >= 2 && !result->uudet) {
      result->uudet = PT_ENCODED;
    }

    result->startpos = prevpos = ftell (datei);
    
    /*
     * If this is Quoted-Printable or Plain Text, just try looking
     * for the next message header. If uu_fast_scanning, we know
     * there won't be more headers.
     * If it is a "trivial" (non-embedded) message/rfc822, skip over
     * the message header and then start looking for the next header.
     */
    if (result->uudet != 0 && uu_fast_scanning) {
      /* do nothing */
      res = 0;
    }
    else if (result->uudet != 0) {
      hcount = lcount = 0;
      prevpos = ftell (datei);

      if (_FP_stristr (sstate.envelope.ctype, "message") != NULL &&
          _FP_stristr (sstate.envelope.ctype, "rfc822")  != NULL) {
        /*
         * skip over empty lines and local header
         */
        preheaders = ftell (datei);
        while (!feof (datei)) {
          if (_FP_fgets (line, 255, datei) == NULL)
            break;
          line[255] = '\0';
          if (!IsLineEmpty (line)) {
            break;
          }
        }

        while (!feof (datei) && !IsLineEmpty (line)) { 
          if (IsKnownHeader (line))
            hcount++;
          lcount++;
          if (lcount > WAITHEADER && hcount < hlcount.afternl)
            break;

          if (_FP_fgets (line, 255, datei) == NULL)
            break;
          line[255] = '\0';
        }
        if (hcount < hlcount.afternl)
          fseek (datei, preheaders, SEEK_SET);
        hcount = lcount = 0;
      }

      /*
       * look for next header
       */

      while (!feof (datei)) {
        if (_FP_fgets (line, 255, datei) == NULL)
          break;
        if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
        if (ferror (datei))
          break;
        line[255] = '\0';

        if (IsKnownHeader (line)) {
          (void) ScanHeaderLine (datei, line);
          if (hcount == 0)
            preheaders = prevpos;
          hcount++;
          lcount++;
          if (hcount >= hlcount.restart) {
            /*
             * Hey, a new header starts here
             */
            fseek (datei, preheaders, SEEK_SET);
            prevpos = preheaders;
            break;
          }
        }
        else if (lcount > WAITHEADER) {
          hcount = 0;
          lcount = 0;
        }
        else if (hcount) {
          lcount++;
        }
        prevpos = ftell (datei);
      }
      res = 1;
    }
    else {
      /*
       * Otherwise, let's see what we can find ourself. No
       * boundary (NULL) but MIME, and respect new headers.
       */
      if ((res = ScanData (datei, fname, errcode, NULL, 1, 1, result)) == -1) {
        /* oops, something went wrong */
        sstate.isfolder = 0;
        sstate.ismime   = 0;
        UUkillfread   (result);
        return NULL;
      }
      if (result->uudet == 0 && uu_handletext) {
        result->startpos = before;      /* display headers */
        result->uudet = PT_ENCODED;
      }

      prevpos = ftell (datei);
    }
    /*
     * produce result
     */
    if (sstate.envelope.fname) {
      _FP_free (result->filename);
      if ((result->filename = _FP_strdup (sstate.envelope.fname)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else if ((result->uudet==QP_ENCODED||result->uudet==PT_ENCODED) &&
             result->filename == NULL) {
      sprintf (line, "%04d.txt", ++mimseqno);
      if ((result->filename = _FP_strdup (line)) == NULL)
        *errcode = UURET_NOMEM;
    }
    else {
      /* assign a filename lateron */
    }
    if (result->subject == NULL) {
      if (sstate.envelope.subject)
        result->subject = _FP_strdup (sstate.envelope.subject);
    }
    result->flags  = ((res==1||uu_fast_scanning)?FL_PROPER:0) |
      ((uu_fast_scanning) ? FL_TOEND : 0);
    result->mimeid = _FP_strdup (sstate.envelope.mimeid);

    if (uu_fast_scanning)
      result->length = progress.fsize - result->startpos;
    else
      result->length = prevpos - result->startpos;

    if (result->sfname == NULL)
      result->sfname = _FP_strdup (fname);

    if (result->mode == 0)
      result->mode = 0644;

    /*
     * the other fields should already be set appropriately
     */

    if (res == 1) {
      /*
       * new headers found
       */
      sstate.isfolder  = 1;
      sstate.ismime    = 0;
      sstate.mimestate = MS_HEADERS;

      UUkillheaders (&sstate.envelope);
      memset (&sstate.envelope, 0, sizeof (headers));
    }
    else {
      /*
       * otherwise, this can't be a mail folder
       */
      sstate.isfolder  = 0;
      sstate.ismime    = 0;
    }

    return result;
  }

  /*
   * Some files have reduced headers, and what should be a multipart
   * message is missing the proper Content-Type. If the first thing
   * we find after a couple of empty lines is a boundary, try it!
   * But make sure that this is indeed intended as being a boundary.
   *
   * Only accept it if there was indeed no Content-Type header line
   * and if the following line is a proper Content-Type header. BTW,
   * we know that sstate.envelope.boundary is NULL, or we wouldn't
   * be here!
   */

  if ((sstate.envelope.ctype == NULL ||
       _FP_stristr (sstate.envelope.ctype, "multipart") != NULL) &&
      !uu_more_mime) {
    prevpos = ftell (datei);
    while (!feof (datei)) {
      if (_FP_fgets (line, 255, datei) == NULL) {
        line[0] = '\0';
        break;
      }
      if (UUBUSYPOLL(ftell(datei),progress.fsize)) SPCANCEL();
      if (!IsLineEmpty (line))
        break;
    }
    if (line[0] == '-' && line[1] == '-' &&
        !IsLineEmpty (line+2) && !feof (datei)) {
      ptr1 = _FP_strrstr (line+2, "--");
      ptr2 = ScanHeaderLine (datei, NULL);
      if ((ptr1 == NULL || (*(ptr1+2) != '\012' && *(ptr1+2) != '\015')) &&
          ptr2 && _FP_strnicmp (ptr2, "Content-", 8) == 0) {
        /*
         * hmm, okay, let's do it!
         */
        sstate.isfolder  = 1;
        sstate.ismime    = 1;
        sstate.mimestate = MS_PREAMBLE;
        /*
         * get boundary
         */
        ptr1 = line+2;
        while (*ptr1 && !isspace(*ptr1))
          ptr1++;
        *ptr1 = '\0';
        
        sstate.envelope.boundary = _FP_strdup (line+2);
        
        /*
         * need restart
         */
        
        fseek (datei, prevpos, SEEK_SET);
        
        _FP_free (result);
        return NULL;
      }
    }
    fseek (datei, prevpos, SEEK_SET);
  }

  /*
   * Hmm, we're not in a ''special'' state, so it's more or less
   * Freestyle time. Anyway, if this seems to be a Mime message,
   * don't allow the minimal Base64 handling.
   */

  if (sstate.envelope.subject)
    result->subject = _FP_strdup (sstate.envelope.subject);
  if (sstate.envelope.from)
    result->origin  = _FP_strdup (sstate.envelope.from);

  if (sstate.envelope.ctype)
    result->mimetype = _FP_strdup (sstate.envelope.ctype);
  
  if ((res=ScanData (datei, fname, errcode, NULL, 
                     sstate.ismime, 1, result))==-1) {
    /* oops, something went wrong */
    sstate.isfolder = 0;
    sstate.ismime   = 0;
    UUkillfread   (result);
    return NULL;
  }
  /*
   * produce result
   */
  if (result->uudet == 0 && uu_handletext) {
    result->startpos = before;  /* display headers */
    result->uudet  = PT_ENCODED;
    result->partno = 1;
  }

  if (sstate.envelope.fname) {
    _FP_free (result->filename);
    if ((result->filename = _FP_strdup (sstate.envelope.fname)) == NULL)
      *errcode = UURET_NOMEM;
  }
  else if ((result->uudet==QP_ENCODED||result->uudet==PT_ENCODED) &&
           result->filename == NULL) {
    sprintf (line, "%04d.txt", ++mimseqno);
    if ((result->filename = _FP_strdup (line)) == NULL)
      *errcode = UURET_NOMEM;
  }
  else {
    /* assign a filename lateron */
  }
  if (result->subject == NULL) {
    if (sstate.envelope.subject)
      result->subject = _FP_strdup (sstate.envelope.subject);
  }

  result->flags  = (result->uudet==PT_ENCODED)?FL_SINGLE:0;
  result->mimeid = _FP_strdup (sstate.envelope.mimeid);
  result->length = ftell (datei) - result->startpos;

  if (result->mode == 0)
    result->mode = 0644;

  if (result->sfname == NULL)
    result->sfname = _FP_strdup (fname);

  if (res == 1) {
    /*
     * new headers found
     */
    sstate.isfolder  = 1;
    sstate.ismime    = 0;
    sstate.mimestate = MS_HEADERS;

    UUkillheaders (&sstate.envelope);
    memset (&sstate.envelope, 0, sizeof (headers));
  }
  else {
    /*
     * otherwise, this can't be a mail folder
     */
    sstate.isfolder  = 0;
    sstate.ismime    = 0;
  }

  return result;

  /*
   * Emergency handling. Set errcode before jumping here.
   */
 ScanPartEmergency:
  UUkillfread   (result);
  UUkillheaders (&localenv);

  while (mssdepth) {
    mssdepth--;
    UUkillheaders (&(multistack[mssdepth].envelope));
    _FP_free (multistack[mssdepth].source);
  }

  return NULL;
}

Revision:	1.3.2.1
Committed:	Sun Mar 31 19:51:30 2002 UTC (22 years, 2 months ago) by root
Content type:	text/plain
Branch:	UUDEVIEW
CVS Tags:	UUDEVIEW-0-5-15
Changes since 1.3:	+248 -263 lines
Log Message:	* empty log message *