diff -r 000000000000 -r 6474c204b198 js/src/jsapi-tests/testArrayBuffer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jsapi-tests/testArrayBuffer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,162 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ */
+
+#include "jsfriendapi.h"
+
+#include "jsapi-tests/tests.h"
+
+BEGIN_TEST(testArrayBuffer_bug720949_steal)
+{
+    static const unsigned NUM_TEST_BUFFERS  = 2;
+    static const unsigned MAGIC_VALUE_1 = 3;
+    static const unsigned MAGIC_VALUE_2 = 17;
+
+    JS::RootedObject buf_len1(cx), buf_len200(cx);
+    JS::RootedObject tarray_len1(cx), tarray_len200(cx);
+
+    uint32_t sizes[NUM_TEST_BUFFERS] = { sizeof(uint32_t), 200 * sizeof(uint32_t) };
+    JS::HandleObject testBuf[NUM_TEST_BUFFERS] = { buf_len1, buf_len200 };
+    JS::HandleObject testArray[NUM_TEST_BUFFERS] = { tarray_len1, tarray_len200 };
+
+    // Single-element ArrayBuffer (uses fixed slots for storage)
+    CHECK(buf_len1 = JS_NewArrayBuffer(cx, sizes[0]));
+    CHECK(tarray_len1 = JS_NewInt32ArrayWithBuffer(cx, testBuf[0], 0, -1));
+
+    JS_SetElement(cx, testArray[0], 0, MAGIC_VALUE_1);
+
+    // Many-element ArrayBuffer (uses dynamic storage)
+    CHECK(buf_len200 = JS_NewArrayBuffer(cx, 200 * sizeof(uint32_t)));
+    CHECK(tarray_len200 = JS_NewInt32ArrayWithBuffer(cx, testBuf[1], 0, -1));
+
+    for (unsigned i = 0; i < NUM_TEST_BUFFERS; i++) {
+        JS::HandleObject obj = testBuf[i];
+        JS::HandleObject view = testArray[i];
+        uint32_t size = sizes[i];
+        JS::RootedValue v(cx);
+
+        // Byte lengths should all agree
+        CHECK(JS_IsArrayBufferObject(obj));
+        CHECK_EQUAL(JS_GetArrayBufferByteLength(obj), size);
+        JS_GetProperty(cx, obj, "byteLength", &v);
+        CHECK_SAME(v, INT_TO_JSVAL(size));
+        JS_GetProperty(cx, view, "byteLength", &v);
+        CHECK_SAME(v, INT_TO_JSVAL(size));
+
+        // Modifying the underlying data should update the value returned through the view
+        uint8_t *data = JS_GetStableArrayBufferData(cx, obj);
+        CHECK(data != nullptr);
+        *reinterpret_cast<uint32_t*>(data) = MAGIC_VALUE_2;
+        CHECK(JS_GetElement(cx, view, 0, &v));
+        CHECK_SAME(v, INT_TO_JSVAL(MAGIC_VALUE_2));
+
+        // Steal the contents
+        void *contents = JS_StealArrayBufferContents(cx, obj);
+        CHECK(contents != nullptr);
+        CHECK(data != nullptr);
+
+        // Check that the original ArrayBuffer is neutered
+        CHECK_EQUAL(JS_GetArrayBufferByteLength(obj), 0);
+        CHECK(JS_GetProperty(cx, obj, "byteLength", &v));
+        CHECK_SAME(v, INT_TO_JSVAL(0));
+        CHECK(JS_GetProperty(cx, view, "byteLength", &v));
+        CHECK_SAME(v, INT_TO_JSVAL(0));
+        CHECK(JS_GetProperty(cx, view, "byteOffset", &v));
+        CHECK_SAME(v, INT_TO_JSVAL(0));
+        CHECK(JS_GetProperty(cx, view, "length", &v));
+        CHECK_SAME(v, INT_TO_JSVAL(0));
+        CHECK_EQUAL(JS_GetArrayBufferByteLength(obj), 0);
+        v = JSVAL_VOID;
+        JS_GetElement(cx, obj, 0, &v);
+        CHECK_SAME(v, JSVAL_VOID);
+
+        // Transfer to a new ArrayBuffer
+        JS::RootedObject dst(cx, JS_NewArrayBufferWithContents(cx, size, contents));
+        CHECK(JS_IsArrayBufferObject(dst));
+        data = JS_GetStableArrayBufferData(cx, obj);
+
+        JS::RootedObject dstview(cx, JS_NewInt32ArrayWithBuffer(cx, dst, 0, -1));
+        CHECK(dstview != nullptr);
+
+        CHECK_EQUAL(JS_GetArrayBufferByteLength(dst), size);
+        data = JS_GetStableArrayBufferData(cx, dst);
+        CHECK(data != nullptr);
+        CHECK_EQUAL(*reinterpret_cast<uint32_t*>(data), MAGIC_VALUE_2);
+        CHECK(JS_GetElement(cx, dstview, 0, &v));
+        CHECK_SAME(v, INT_TO_JSVAL(MAGIC_VALUE_2));
+    }
+
+    return true;
+}
+END_TEST(testArrayBuffer_bug720949_steal)
+
+// Varying number of views of a buffer, to test the neutering weak pointers
+BEGIN_TEST(testArrayBuffer_bug720949_viewList)
+{
+    JS::RootedObject buffer(cx);
+
+    // No views
+    buffer = JS_NewArrayBuffer(cx, 2000);
+    buffer = nullptr;
+    GC(cx);
+
+    // One view.
+    {
+        buffer = JS_NewArrayBuffer(cx, 2000);
+        JS::RootedObject view(cx, JS_NewUint8ArrayWithBuffer(cx, buffer, 0, -1));
+        void *contents = JS_StealArrayBufferContents(cx, buffer);
+        CHECK(contents != nullptr);
+        JS_free(nullptr, contents);
+        GC(cx);
+        CHECK(isNeutered(view));
+        CHECK(isNeutered(buffer));
+        view = nullptr;
+        GC(cx);
+        buffer = nullptr;
+        GC(cx);
+    }
+
+    // Two views
+    {
+        buffer = JS_NewArrayBuffer(cx, 2000);
+
+        JS::RootedObject view1(cx, JS_NewUint8ArrayWithBuffer(cx, buffer, 0, -1));
+        JS::RootedObject view2(cx, JS_NewUint8ArrayWithBuffer(cx, buffer, 1, 200));
+
+        // Remove, re-add a view
+        view2 = nullptr;
+        GC(cx);
+        view2 = JS_NewUint8ArrayWithBuffer(cx, buffer, 1, 200);
+
+        // Neuter
+        void *contents = JS_StealArrayBufferContents(cx, buffer);
+        CHECK(contents != nullptr);
+        JS_free(nullptr, contents);
+
+        CHECK(isNeutered(view1));
+        CHECK(isNeutered(view2));
+        CHECK(isNeutered(buffer));
+
+        view1 = nullptr;
+        GC(cx);
+        view2 = nullptr;
+        GC(cx);
+        buffer = nullptr;
+        GC(cx);
+    }
+
+    return true;
+}
+
+static void GC(JSContext *cx)
+{
+    JS_GC(JS_GetRuntime(cx));
+    JS_GC(JS_GetRuntime(cx)); // Trigger another to wait for background finalization to end
+}
+
+bool isNeutered(JS::HandleObject obj) {
+    JS::RootedValue v(cx);
+    return JS_GetProperty(cx, obj, "byteLength", &v) && v.toInt32() == 0;
+}
+
+END_TEST(testArrayBuffer_bug720949_viewList)