Merged revisions 231911 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r231911 | jpeeler | 2009-12-01 15:29:31 -0600 (Tue, 01 Dec 2009) | 12 lines
  
  Fix crash with invalid frame data
  
  The crash was happening as a result of a frame containing an invalid data
  pointer, but was set with data length of zero. The few times the issue was
  reproduced it _seemed_ that the frame was queued properly, that is the data
  pointer was set to NULL. I never could reproduce the crash so as a last resort
  the crash has been fixed, but a check in __ast_read has been added to give as
  much information about the source of problematic frames in the future.
  
  (closes issue #16058)
  Reported by: atis
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@231927 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/channel.c

@@ -3519,6 +3519,17 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 		ast_frame_dump(chan->name, f, "<<");
 	chan->fin = FRAMECOUNT_INC(chan->fin);
 
+	if (f && f->datalen == 0 && f->data.ptr) {
+		/* fix invalid pointer */
+		f->data.ptr = NULL;
+#ifdef AST_DEVMODE
+		ast_log(LOG_ERROR, "Found frame with src '%s' on channel '%s' with datalen zero, but non-null data pointer!\n", f->src, chan->name);
+		ast_frame_dump(chan->name, f, "<<");
+#else
+		ast_debug(3, "Found frame with src '%s' on channel '%s' with datalen zero, but non-null data pointer!\n", f->src, chan->name);
+#endif
+	}
+
 done:
 	if (chan->music_state && chan->generator && chan->generator->digit && f && f->frametype == AST_FRAME_DTMF_END)
 		chan->generator->digit(chan, f->subclass.integer);