--- frame.c.20070226	2007-02-26 23:05:01.000000000 -0500
+++ frame.c	2007-02-26 23:05:56.000000000 -0500
@@ -427,6 +427,9 @@
 	int len, srclen = 0;
 	void *buf = NULL;
 
+	if(!f)
+		return NULL;
+
 	/* Start with standard stuff */
 	len = sizeof(*out) + AST_FRIENDLY_OFFSET + f->datalen;
 	/* If we have a source, add space for it */