Merged revisions 346762 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.8

........
  r346762 | may | 2011-12-02 20:19:19 +0400 (Fri, 02 Dec 2011) | 7 lines
  
  process null frame pointer returned by ast_rtp_instance_read correctly
  
  (closes issue ASTERISK-16697)
  Reported by: under
  Patches: 
          segfault.diff (License #5871) patch uploaded by under
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@346763 65c4cc65-6c06-0410-ace0-fbb531ad65f3

addons/chan_ooh323.c

@@ -4576,7 +4576,7 @@ struct ast_frame *ooh323_rtp_read(struct ast_channel *ast, struct ooh323_pvt *p)
 		f = &null_frame;
 	}
 
-	if (p->owner && !p->faxmode && (f->frametype == AST_FRAME_VOICE)) {
+	if (f && p->owner && !p->faxmode && (f->frametype == AST_FRAME_VOICE)) {
 		/* We already hold the channel lock */
 		if (!(ast_format_cap_iscompatible(p->owner->nativeformats, &f->subclass.format))) {
 			ast_debug(1, "Oooh, voice format changed to %s\n", ast_getformatname(&f->subclass.format));

channels/chan_h323.c

@@ -772,7 +772,7 @@ static struct ast_frame *oh323_rtp_read(struct oh323_pvt *pvt)
 	if (f && (f->frametype == AST_FRAME_DTMF) && !(pvt->options.dtmfmode & (H323_DTMF_RFC2833 | H323_DTMF_CISCO))) {
 		return &ast_null_frame;
 	}
-	if (pvt->owner) {
+	if (f && pvt->owner) {
 		/* We already hold the channel lock */
 		if (f->frametype == AST_FRAME_VOICE) {
 			if (!ast_format_cap_iscompatible(pvt->owner->nativeformats, &f->subclass.format)) {