From: Michael Elkins <me@sigpipe.org>
Date: Sat, 11 Sep 2010 14:28:48 +0000 (-0700)
Subject: more lenient RFC2047 decoding: accept illegal spaces and bare question marks in encod... 
X-Git-Tag: mutt-1-5-21-rel~11
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9adcddd20bf0524b2e4995ec229dc2331f18eff8;p=mutt

more lenient RFC2047 decoding: accept illegal spaces and bare question marks in encoded words
---

diff --git a/rfc2047.c b/rfc2047.c
index 8d496253..7a117118 100644
--- a/rfc2047.c
+++ b/rfc2047.c
@@ -629,12 +629,23 @@ static int rfc2047_decode_word (char *d, const char *s, size_t len)
   const char *t, *t1;
   int enc = 0, count = 0;
   char *charset = NULL;
+  int rv = -1;
 
   pd = d0 = safe_malloc (strlen (s));
 
   for (pp = s; (pp1 = strchr (pp, '?')); pp = pp1 + 1)
   {
     count++;
+
+    /* hack for non-compliant MUAs that allow unquoted question marks in encoded-text */
+    if (count == 4)
+    {
+      while (pp1 && *(pp1 + 1) != '=')
+	pp1 = strchr(pp1 + 1, '?');
+      if (!pp1)
+	  goto error_out_0;
+    }
+
     switch (count)
     {
       case 2:
@@ -650,11 +661,7 @@ static int rfc2047_decode_word (char *d, const char *s, size_t len)
 	else if (toupper ((unsigned char) *pp) == 'B')
 	  enc = ENCBASE64;
 	else
-	{
-	  FREE (&charset);
-	  FREE (&d0);
-	  return (-1);
-	}
+	  goto error_out_0;
 	break;
       case 4:
 	if (enc == ENCQUOTEDPRINTABLE)
@@ -707,9 +714,11 @@ static int rfc2047_decode_word (char *d, const char *s, size_t len)
     mutt_convert_string (&d0, charset, Charset, M_ICONV_HOOK_FROM);
   mutt_filter_unprintable (&d0);
   strfcpy (d, d0, len);
+  rv = 0;
+error_out_0:
   FREE (&charset);
   FREE (&d0);
-  return (0);
+  return rv;
 }
 
 /*
@@ -731,7 +740,8 @@ static const char *find_encoded_word (const char *s, const char **x)
       ;
     if (q[0] != '?' || !strchr ("BbQq", q[1]) || q[2] != '?')
       continue;
-    for (q = q + 3; 0x20 < *q && *q < 0x7f && *q != '?'; q++)
+    /* non-strict check since many MUAs will not encode spaces and question marks */
+    for (q = q + 3; 0x20 <= *q && *q < 0x7f && (*q != '?' || q[1] != '='); q++)
       ;
     if (q[0] != '?' || q[1] != '=')
     {