diff -udpr mutt-1.2.5.orig/attach.c mutt-1.2.5/attach.c
--- mutt-1.2.5.orig/attach.c	Fri Mar  3 11:10:06 2000
+++ mutt-1.2.5/attach.c	Sun Apr 29 13:29:11 2001
@@ -325,6 +325,27 @@ static int is_mmnoask (const char *buf)
   return (0);
 }
 
+void mutt_lookup_octetstream (BODY *b, char *type, int len)
+{
+  if (option (OPTLOOKUPOCTETSTREAM) &&
+      ! mutt_strcasecmp ("application/octet-stream", type)) {
+    char buf[SHORT_STRING];
+    int n;
+    if ((n = mutt_lookup_mime_type (buf, b->filename)) != TYPEOTHER) {
+      snprintf (type, len, "%s/%s",
+                n == TYPEAUDIO ? "audio" :
+                n == TYPEAPPLICATION ? "application" :
+                n == TYPEIMAGE ? "image" :
+                n == TYPEMESSAGE ? "message" :
+                n == TYPEMODEL ? "model" :
+                n == TYPEMULTIPART ? "multipart" :
+                n == TYPETEXT ? "text" :
+                n == TYPEVIDEO ? "video" : "other",
+                buf);
+    }
+  }
+}
+
 int mutt_is_autoview (BODY *b, const char *type)
 {
   LIST *t = AutoViewList;
@@ -332,10 +353,12 @@ int mutt_is_autoview (BODY *b, const cha
   int i;
 
   if (!type)
-  {
     snprintf (_type, sizeof (_type), "%s/%s", TYPE (b), b->subtype);
-    type = _type;
-  }
+  else
+    strncpy (_type, type, sizeof(_type));
+
+  mutt_lookup_octetstream (b, _type, sizeof(_type));
+  type = _type;
 
   if (mutt_needs_mailcap (b))
   {
diff -udpr mutt-1.2.5.orig/init.h mutt-1.2.5/init.h
--- mutt-1.2.5.orig/init.h	Tue Jul 18 09:47:08 2000
+++ mutt-1.2.5/init.h	Sun Apr 29 13:29:11 2001
@@ -845,6 +845,17 @@ struct option_t MuttVars[] = {
   ** The locale used by \fIstrftime(3)\fP to format dates. Legal values are
   ** the strings your system accepts for the locale variable \fILC_TIME\fP.
   */
+  { "lookup_octetstream", DT_BOOL, R_NONE, OPTLOOKUPOCTETSTREAM, 0 },
+  /*
+  ** .pp
+  ** This variable controls whether "application/octet-stream" attachments
+  ** should be dealt with especially. If set, Mutt will, when viewing
+  ** octet-streams, search the 'mime.types' file for an entry matching
+  ** the file extension. If a match is found the file is viewed according
+  ** to the found mime-type's entry in the mailcap file, otherwise the
+  ** application-octetstream entry in the mailcap file is used. All
+  ** attachments not labeled application/octet-stream are handled normally.
+  */
   { "mail_check",      DT_NUM,  R_NONE, UL &BuffyTimeout, 5 },
   /*
   ** .pp
diff -udpr mutt-1.2.5.orig/mutt.h mutt-1.2.5/mutt.h
--- mutt-1.2.5.orig/mutt.h	Thu Jun  8 12:00:14 2000
+++ mutt-1.2.5/mutt.h	Sun Apr 29 13:29:11 2001
@@ -312,6 +312,7 @@ enum
   OPTSSLSYSTEMCERTS,
 #endif
   OPTIMPLICITAUTOVIEW,
+  OPTLOOKUPOCTETSTREAM,
   OPTMAILCAPSANITIZE,
   OPTMARKERS,
   OPTMARKOLD,
diff -udpr mutt-1.2.5.orig/protos.h mutt-1.2.5/protos.h
--- mutt-1.2.5.orig/protos.h	Tue May 16 17:23:12 2000
+++ mutt-1.2.5/protos.h	Sun Apr 29 13:29:11 2001
@@ -163,6 +163,7 @@ void mutt_free_parameter (PARAMETER **);
 void mutt_generate_header (char *, size_t, HEADER *, int);
 void mutt_help (int);
 void mutt_linearize_tree (CONTEXT *, int);
+void mutt_lookup_octetstream (BODY *, char *, int);
 void mutt_make_attribution (CONTEXT *ctx, HEADER *cur, FILE *out);
 void mutt_make_forward_subject (ENVELOPE *env, CONTEXT *ctx, HEADER *cur);
 void mutt_make_help (char *, size_t, char *, int, int);
@@ -257,6 +258,7 @@ int mutt_is_list_recipient (int, ADDRESS
 int mutt_is_subscribed_list (ADDRESS *);
 int mutt_is_text_type (int, char *);
 int mutt_is_valid_mailbox (const char *);
+int mutt_lookup_mime_type (char *, const char *);
 int mutt_multi_choice (char *prompt, char *letters);
 int mutt_needs_mailcap (BODY *);
 int mutt_num_postponed (int);
diff -udpr mutt-1.2.5.orig/rfc1524.c mutt-1.2.5/rfc1524.c
--- mutt-1.2.5.orig/rfc1524.c	Fri Mar  3 11:10:13 2000
+++ mutt-1.2.5/rfc1524.c	Sun Apr 29 13:29:11 2001
@@ -392,6 +392,8 @@ int rfc1524_mailcap_lookup (BODY *a, cha
     return 0;
   }
 
+  mutt_lookup_octetstream (a, type, SHORT_STRING);
+
   while (!found && *curr)
   {
     x = 0;
diff -udpr mutt-1.2.5.orig/sendlib.c mutt-1.2.5/sendlib.c
--- mutt-1.2.5.orig/sendlib.c	Sat May 20 08:38:59 2000
+++ mutt-1.2.5/sendlib.c	Sun Apr 29 13:29:11 2001
@@ -626,7 +626,7 @@ static CONTENT *mutt_get_content_info (c
  * exists.
  */
 
-static int lookup_mime_type (char *d, const char *s)
+int mutt_lookup_mime_type (char *d, const char *s)
 {
   FILE *f;
   char *p, *ct,
@@ -1076,7 +1076,7 @@ BODY *mutt_make_file_attach (const char 
    * suffix.
    */
 
-  if ((n = lookup_mime_type (buf, path)) != TYPEOTHER)
+  if ((n = mutt_lookup_mime_type (buf, path)) != TYPEOTHER)
   {
     att->type = n;
     att->subtype = safe_strdup (buf);