From 2b5c4b6975a493ccf12a48b78759a4cada7649f8 Mon Sep 17 00:00:00 2001
From: Robert Krimen <robertkrimen@gmail.com>
Date: Wed, 21 Nov 2012 18:19:15 -0800
Subject: [PATCH] Safeguard RegExp.exec against non-RegExp

---
 otto_test.go   | 5 +++++
 type_regexp.go | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/otto_test.go b/otto_test.go
index 26c108e..f8a38e2 100644
--- a/otto_test.go
+++ b/otto_test.go
@@ -1655,6 +1655,11 @@ func TestRegExp_exec(t *testing.T) {
 		}
 		[ ghi, lastIndex ];
 	`, "3,7")
+
+	test(`raise:
+		var exec = RegExp.prototype.exec;
+		exec("Xyzzy");
+	`, "TypeError: Calling RegExp.exec on a non-RegExp object")
 }
 
 func TestNewFunction(t *testing.T) {
diff --git a/type_regexp.go b/type_regexp.go
index a1ecf57..ea68cb9 100644
--- a/type_regexp.go
+++ b/type_regexp.go
@@ -68,6 +68,9 @@ func (runtime *_runtime) newRegExpObject(pattern string, flags string) *_object
 }
 
 func execRegExp(this *_object, target string) (match bool, result []int) {
+	if this.class != "RegExp" {
+		panic(newTypeError("Calling RegExp.exec on a non-RegExp object"))
+	}
 	lastIndex := toInteger(this.get("lastIndex"))
 	index := lastIndex
 	global := toBoolean(this.get("global"))