# Add minimal multipart support to slrn
# text type parts are displayed correctly
# binary and other unsupported parts are hidden
#
# Don't expect it to read html postings or
# to save binary attachments, it just helps to
# ease the pain when reading pgp/mime signed
# postings or postings created by pine.
#
# You can disable the minimal multipart support by
# adding "set minimal_multipart 0" in your slrnrc.
#
# Thanks to Christian Ebert. He helped a lot to
# debug this patch, thus you could call it
# now quite stable.
#
# send bugs and other feedback to wiegner(at)gmx.de
#
# Thomas Wiegner
#
# Changelog
#
#  2007-07-10  - Fixed bug with nested multiparts
#              - Fixed bug with base64 encoded parts
#  2007-07-14  - Fixed crash due to uninitialized pointers
#  2007-07-24  - Code cleanup, no crash due to corrupted multipart postings
#  2007-08-02  - disable/enable via slrnrc
#  2007-08-18  - Fixed possible crash when decoding qp parts
#  2007-09-06  - Fixed line->prev of pseudeo article
#  2007-10-21  - Adapted to 0.9.9 version of slrn
#  2007-11-09  - Decode headers of multipart postings correctly
#  2007-12-01  - signatures are ended correctly inside multipart
#  2008-02-10  - Changed place to add "mm" to version string

Index: src/art_misc.c
===================================================================
--- src/art_misc.c	(revision 262)
+++ src/art_misc.c	(working copy)
@@ -406,6 +406,7 @@
    
    while (l != NULL)
      {
+        if(l->flags & HIDDEN_LINE) break;
         l->flags |= SIGNATURE_LINE;
         l->flags &= ~(
 		      QUOTE_LINE  /* if in a signature, not a quote */
Index: src/version.c
===================================================================
--- src/version.c	(revision 262)
+++ src/version.c	(working copy)
@@ -43,7 +43,8 @@
 #include "art.h"
 #include "snprintf.h"
 
-char *Slrn_Version_String = SLRN_VERSION_STRING;
+#define SLRN_VERSION_STRING_TW SLRN_VERSION_STRING"/mm"
+char *Slrn_Version_String = SLRN_VERSION_STRING_TW;
 int Slrn_Version = SLRN_VERSION;
 
 typedef struct 
@@ -91,6 +92,12 @@
    {NULL, 0}
 };
 
+static char *included_patches[] =
+{
+ "minimal_multipart",
+ ""
+};
+
 static void print_options (FILE *fp, Compile_Option_Type *opts, char *title)
 {
    unsigned int len;
@@ -121,6 +128,17 @@
    print_options (fp, Feature_Options, _("Features"));
 }
 
+static void show_included_patches (FILE *fp)
+{
+  int i=0;
+
+  while(*(included_patches[i]) != '\0')
+  {
+    fprintf (fp, _("  %s\n"),included_patches[i]);
+    i++;
+  }
+}
+
 void slrn_show_version (FILE *fp) /*{{{*/
 {
    char *os;
@@ -150,6 +168,12 @@
    
    fprintf (fp, _(" Default posting mechanism: %s\n"),
 	    slrn_map_object_id_to_name (1, SLRN_DEFAULT_POST_OBJ));
+
+   if(*included_patches[0] != '\0')
+   {
+      fprintf (fp, _("\nPATCHES:\n"));
+      show_included_patches (fp);
+   }
 }
 
 /*}}}*/
Index: src/mime.c
===================================================================
--- src/mime.c	(revision 262)
+++ src/mime.c	(working copy)
@@ -55,6 +55,7 @@
 int Slrn_Use_Meta_Mail = 1;
 int Slrn_Fold_Headers = 1;
 char *Slrn_MetaMail_Cmd;
+int Slrn_Minimal_Multipart =1;
 
 #ifndef SLRNPULL_CODE
 #define CONTENT_TYPE_TEXT		0x01
@@ -106,17 +107,60 @@
 	  }
 	b += 5;
      }
-   else if (0 == slrn_case_strncmp (b, "message/", 5))
+   else if (0 == slrn_case_strncmp (b, "message/", 8))
      {
 	a->mime.content_type = CONTENT_TYPE_MESSAGE;
 	a->mime.content_subtype = CONTENT_SUBTYPE_UNKNOWN;
 	b += 8;
      }
-   else if (0 == slrn_case_strncmp (b, "multipart/", 5))
+     else if (0 == slrn_case_strncmp (b, "application/", 12))
+      {
+ 	b += 12;
+ 	if (0 != slrn_case_strncmp (b, "pgp-signature", 13))
+ 	  {
+ 	     a->mime.content_type = CONTENT_TYPE_UNSUPPORTED;
+ 	     a->mime.content_subtype = CONTENT_SUBTYPE_UNSUPPORTED;
+ 	     return -1;
+ 	  }
+ 	a->mime.content_type = CONTENT_TYPE_TEXT;
+ 	a->mime.content_subtype = CONTENT_SUBTYPE_PLAIN;
+      }
+   else if (0 == slrn_case_strncmp (b, "multipart/", 10))
      {
 	a->mime.content_type = CONTENT_TYPE_MULTIPART;
 	a->mime.content_subtype = CONTENT_SUBTYPE_UNKNOWN;
 	b += 10;
+ 	while (NULL != (b = slrn_strbyte(b, ';')))
+ 	  {
+ 	     char *boundary;
+ 	     unsigned int len;
+ 	     
+ 	     b = slrn_skip_whitespace (b + 1);
+ 	     
+ 	     if (0 != slrn_case_strncmp (b, "boundary", 8))
+ 	       continue;
+ 	     
+ 	     b = slrn_skip_whitespace (b + 8);
+ 
+ 	     if (*b != '=') continue;
+ 	     b++;
+ 	     if (*b == '"') b++;
+ 	     boundary = b;
+ 	     while (*b && (*b != ';')
+ 		    && (*b != ' ') && (*b != '\t') && (*b != '\n')
+ 		    && (*b != '"'))
+ 	       b++;
+ 	     len = b - boundary;
+ 
+              /* add a "--" at the start of boundary */
+ 	     a->mime.boundary = slrn_safe_malloc(len+5);
+              a->mime.boundary[0]='-';
+              a->mime.boundary[1]='-';
+              slrn_strncpy(a->mime.boundary+2, boundary, len+1);
+              a->mime.boundary[len+2]='-';
+              a->mime.boundary[len+3]='-';
+ 	     return 0;
+ 	  }
      }
    else
      {
@@ -786,6 +830,7 @@
    m->was_parsed = 0;
    m->needs_metamail = 0;
    m->charset = NULL;
+   m->boundary = NULL;
    m->content_type = 0;
    m->content_subtype = 0;
 }
@@ -798,6 +843,10 @@
     {
        slrn_free(m->charset);
     }
+  if (m->boundary != NULL)
+    {
+       slrn_free(m->boundary);
+    }
 }
 
 /*}}}*/
@@ -883,7 +932,118 @@
 	obj=tmp;
      }
 }
+/*}}}*/
 
+int slrn_convert_multipart_article(Slrn_Article_Type *a, char *to_charset)/*{{{*/
+{
+   struct Slrn_Article_Line_Type *line, *first_line,  *line_start_part, *line_end_part, *line_tmp;
+   int len;
+   int j=1;
+   int endfound=0;
+
+   Slrn_Mime_Type mime_bak;
+
+   first_line =a->lines;
+   line       =a->lines;
+   len = strlen(a->mime.boundary)-2;
+   /* search 1st boundary */ 
+   do
+   {
+      if((line->flags & HEADER_LINE) == 0)
+      {
+        line->flags |= HIDDEN_LINE;
+      }
+      line=line->next;
+   } while ((line->next != NULL) && slrn_case_strncmp(line->buf, a->mime.boundary, len) != 0);
+
+   while ((line->next != NULL) && (endfound == 0))
+     {
+       j++;
+       line_start_part = line;
+       do
+       {
+         line->flags |= HIDDEN_LINE;
+         line->flags |= HEADER_LINE;
+         line=line->next; 
+
+       } while ((line->next != NULL) && (*(line->buf) != 0));
+      
+       /* search boundary */
+       while ((line->next != NULL) && (slrn_case_strncmp(line->buf, a->mime.boundary, len) != 0))
+       {
+         line_end_part=line;
+         line=line->next;
+       }
+       if(slrn_case_strncmp(line->buf, a->mime.boundary, len+2) == 0)
+       {
+         /* we found the normal ending boundary */
+         endfound=1;
+       }
+       else if(line->next==NULL)
+       {
+         /* end of article, indicating a corrupted article */
+         endfound=2;
+       }
+
+       /* pseudo article with only multipart */
+       mime_bak = a->mime;
+       slrn_mime_init(&a->mime);
+       a->lines = line_start_part;
+
+       /* start of pseudo article has no prev, save old prev value in line_start_part */
+       line_start_part=line_start_part->prev;
+       a->lines->prev = NULL;
+
+       if(endfound != 2)
+       {
+         line_end_part->next = NULL;
+       }
+
+       _slrn_art_unfold_header_lines(a);
+       slrn_mime_process_article (a);
+
+       line->flags |= HIDDEN_LINE;
+       line_tmp = a->lines;
+       do 
+       {
+           if( line_tmp->flags & HEADER_LINE)
+             {
+               line_tmp->flags ^= HEADER_LINE;
+             }
+           else if(a->mime.content_type == CONTENT_TYPE_UNSUPPORTED)
+             {
+               /* hide not supported multiparts */
+               line_tmp->flags |= HIDDEN_LINE;
+             }
+           line_end_part=line_tmp;
+           line_tmp=line_tmp->next;
+       } while (line_tmp != NULL);
+
+       /* set back article */ 
+       line_start_part->next=a->lines;
+       a->lines->prev=line_start_part;
+
+       a->lines = first_line;
+       if(endfound != 2)
+       {
+         line_end_part->next = line;
+         line->prev          = line_end_part;
+       }
+       else
+       {
+         slrn_message (_("Multipart article is corrupted."));
+       }
+
+       if(a->mime.content_type == CONTENT_TYPE_UNSUPPORTED)
+         slrn_message (_("Unsupported multiparts were hidden."));
+
+       /* free space */
+       slrn_mime_free(&a->mime);
+
+       a->mime=mime_bak;
+     }
+   return 0;
+}
 /*}}}*/
 
 static char *guess_body_charset (Slrn_Article_Type *a)
@@ -938,13 +1098,18 @@
 	a->mime.needs_metamail = 1;
 	return 0;
      }
-   
+
    if ((a->mime.charset == NULL)
        && (NULL == (a->mime.charset = guess_body_charset (a))))
      return -1;
 
    rfc1522_decode_headers (a);
 
+   if ((a->mime.content_type == CONTENT_TYPE_MULTIPART) && (Slrn_Minimal_Multipart != 0) )
+     {
+	return slrn_convert_multipart_article(a, Slrn_Display_Charset);
+     }
+   
    switch (parse_content_transfer_encoding_line (a))
      {
       case ENCODED_RAW:
Index: src/mime.h
===================================================================
--- src/mime.h	(revision 262)
+++ src/mime.h	(working copy)
@@ -34,6 +34,7 @@
 extern int Slrn_Fold_Headers;
 extern int Slrn_Use_Meta_Mail;
 extern char *Slrn_MetaMail_Cmd;
+extern int Slrn_Minimal_Multipart;
 
 
 #endif /* _SLRN_MIME_H */
Index: src/startup.c
===================================================================
--- src/startup.c	(revision 262)
+++ src/startup.c	(working copy)
@@ -639,6 +639,7 @@
      {"max_queued_groups", &Slrn_Max_Queued_Groups, NULL},
      {"use_header_numbers", &Slrn_Use_Header_Numbers, NULL},
      {"use_localtime", &Slrn_Use_Localtime, NULL},
+     {"minimal_multipart", &Slrn_Minimal_Multipart},
 #if SLRN_HAS_SPOILERS
      {"spoiler_char", &Slrn_Spoiler_Char, NULL},
      {"spoiler_display_mode", &Slrn_Spoiler_Display_Mode, NULL},
Index: src/art.h
===================================================================
--- src/art.h	(revision 262)
+++ src/art.h	(working copy)
@@ -185,6 +185,7 @@
     int was_modified;
     int was_parsed;
     int needs_metamail;
+    char *boundary;
 }
 Slrn_Mime_Type;