markm committed a patch I was working on yesterday, this fixes it to mesh up with suggestions by mnicholson.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@321273 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/sip/reqresp_parser.c

@@ -42,9 +42,11 @@ int parse_uri_full(char *uri, const char *scheme, char **user, char **pass,
 	char *c = NULL;
 	int error = 0;
 
-	/* check for valid input */
-	if (ast_strlen_zero(uri)) {
-		/* make sure we leave nothing undefined after we exit */
+	/*
+	 * Initialize requested strings - some functions don't care if parse_uri fails
+	 * and will attempt to use string pointers passed into parse_uri even after a
+	 * parse_uri failure
+	 */
 	if (user) {
 		*user = "";
 	}
@@ -61,6 +63,8 @@ int parse_uri_full(char *uri, const char *scheme, char **user, char **pass,
 		*residue = "";
 	}
 
+	/* check for valid input */
+	if (ast_strlen_zero(uri)) {
 		return -1;
 	}