GetVal return 0 when match failed (#2539)

gframe/bufferio.h

@@ -133,7 +133,9 @@ public:
 			ret = ret * 10 + (*pstr - L'0');
 			pstr++;
 		}
-		return (int)ret;
+		if (*pstr == 0)
+			return (int)ret;
+		return 0;
 	}
 };