diff -r 000000000000 -r 6474c204b198 js/src/jsapi-tests/testEnclosingFunction.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsapi-tests/testEnclosingFunction.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,65 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ *
+ * Test script cloning.
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jsfriendapi.h"
+
+#include "js/OldDebugAPI.h"
+#include "jsapi-tests/tests.h"
+
+using namespace js;
+
+static JSScript *foundScript = nullptr;
+
+static bool
+CheckEnclosing(JSContext *cx, unsigned argc, Value *vp)
+{
+    CallArgs args = CallArgsFromVp(argc, vp);
+
+    foundScript = js::GetOutermostEnclosingFunctionOfScriptedCaller(cx);
+
+    args.rval().set(UndefinedValue());
+    return true;
+}
+
+BEGIN_TEST(test_enclosingFunction)
+{
+    CHECK(JS_DefineFunction(cx, global, "checkEnclosing", CheckEnclosing, 0, 0));
+
+    EXEC("checkEnclosing()");
+    CHECK(foundScript == nullptr);
+
+    RootedFunction fun(cx);
+
+    JS::CompileOptions options(cx);
+    options.setFileAndLine(__FILE__, __LINE__);
+
+    const char s1chars[] = "checkEnclosing()";
+    fun = JS_CompileFunction(cx, global, "s1", 0, nullptr, s1chars,
+                             strlen(s1chars), options);
+    CHECK(fun);
+    EXEC("s1()");
+    CHECK(foundScript == JS_GetFunctionScript(cx, fun));
+
+    const char s2chars[] = "return function() { checkEnclosing() }";
+    fun = JS_CompileFunction(cx, global, "s2", 0, nullptr, s2chars,
+                             strlen(s2chars), options);
+    CHECK(fun);
+    EXEC("s2()()");
+    CHECK(foundScript == JS_GetFunctionScript(cx, fun));
+
+    const char s3chars[] = "return function() { let (x) { function g() { checkEnclosing() } return g() } }";
+    fun = JS_CompileFunction(cx, global, "s3", 0, nullptr, s3chars,
+                             strlen(s3chars), options);
+    CHECK(fun);
+    EXEC("s3()()");
+    CHECK(foundScript == JS_GetFunctionScript(cx, fun));
+
+    return true;
+}
+END_TEST(test_enclosingFunction)