chan_misdn.c:process_ast_dsp() memory leak

misdn.conf: astdtmf must be set to "yes".  With "no", buffer loss does not
occur.

The translated frame "f2" when passing through ast_dsp_process() is not
freed whenever it is not used further in process_ast_dsp().  Then in the
end it is never ever freed.

Patches:
      translate.patch

JIRA ABE-1993


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@222691 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_misdn.c

@@ -2715,8 +2715,12 @@ static struct ast_frame *process_ast_dsp(struct chan_list *tmp, struct ast_frame
 		return NULL;
 	}
 
- 	if (!f || (f->frametype != AST_FRAME_DTMF))
- 		return frame;
+	if (!f || (f->frametype != AST_FRAME_DTMF)) {
+		if (f) {
+			ast_frfree(f);
+		}
+		return frame;
+	}
  
  	ast_log(LOG_DEBUG, "Detected inband DTMF digit: %c\n", f->subclass);