Graceful handling of new versions of IndexedDB serialized data.

third_party/WebKit/Source/bindings/modules/v8/V8BindingForModulesTest.cpp

Index: third_party/WebKit/Source/bindings/modules/v8/V8BindingForModulesTest.cpp
diff --git a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModulesTest.cpp b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModulesTest.cpp
index 9c23c90eb51dbfbc854a10b7428d6eebea9945c9..3fb2c598f644d0a6ab49c984f91921365459b1c1 100644
--- a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModulesTest.cpp
+++ b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModulesTest.cpp
@@ -25,13 +25,24 @@
 
 #include "bindings/modules/v8/V8BindingForModules.h"
 
+#include "bindings/core/v8/SerializationTag.h"
+#include "bindings/core/v8/SerializedScriptValue.h"
 #include "bindings/core/v8/ToV8.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8BindingForTesting.h"
 #include "bindings/core/v8/V8PerIsolateData.h"
 #include "bindings/modules/v8/ToV8ForModules.h"
+#include "modules/indexeddb/IDBAny.h"
 #include "modules/indexeddb/IDBKey.h"
 #include "modules/indexeddb/IDBKeyPath.h"
+#include "modules/indexeddb/IDBValue.h"
+#include "platform/SharedBuffer.h"
+#include "public/platform/WebBlobInfo.h"
+#include "public/platform/WebData.h"
+#include "public/platform/WebString.h"
+#include "public/platform/modules/indexeddb/WebIDBKey.h"
+#include "public/platform/modules/indexeddb/WebIDBKeyPath.h"
+#include "public/platform/modules/indexeddb/WebIDBValue.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
@@ -116,6 +127,62 @@ void checkKeyPathNumberValue(v8::Isolate* isolate,
   ASSERT_TRUE(expected == idbKey->number());
 }
 
+// SerializedScriptValue header format offsets are inferred from the Blink and
+// V8 serialization code. The code below DCHECKs that

[jsbell, 2017/04/04 16:42:34]

nit: truncated comment?

+constexpr static size_t kSSVHeaderBlinkVersionOffset = 0;
+constexpr static size_t kSSVHeaderBlinkVersionTagOffset = 1;
+constexpr static size_t kSSVHeaderV8VersionOffset = 2;
+constexpr static size_t kSSVHeaderV8VersionTagOffset = 3;
+
+// 13 is v8::internal::kLatestVersion in v8/src/value-serializer.cc at the
+// time when this test was written. Unlike Blink, V8 does not currently export
+// its serialization version, so this number might get stale.

[jsbell, 2017/04/04 16:42:34]

TODO(jbroman): Update when it is exported by v8.

+constexpr static unsigned char kV8LatestKnownVersion = 13;
+
+// Follows the same steps as the IndexedDB value serialization code.
+void serializeV8Value(v8::Local<v8::Value> value,
+                      v8::Isolate* isolate,
+                      Vector<char>* wireBytes) {
+  NonThrowableExceptionState nonThrowableExceptionState;
+
+  SerializedScriptValue::SerializeOptions options;
+  RefPtr<SerializedScriptValue> serializedValue =
+      SerializedScriptValue::serialize(isolate, value, options,
+                                       nonThrowableExceptionState);
+  serializedValue->toWireBytes(*wireBytes);
+
+  // Sanity check that the serialization header has not changed, as the tests
+  // that use this method rely on the header format.
+  //
+  // The cast from char* to unsigned char* is necessary to avoid VS2015 warning
+  // C4309 (truncation of constant value). This happens because VersionTag is
+  // 0xFF.
+  const unsigned char* wireData =
+      reinterpret_cast<unsigned char*>(wireBytes->data());
+  ASSERT_EQ(
+      static_cast<unsigned char>(SerializedScriptValue::wireFormatVersion),
+      wireData[kSSVHeaderBlinkVersionOffset]);
+  ASSERT_EQ(static_cast<unsigned char>(VersionTag),
+            wireData[kSSVHeaderBlinkVersionTagOffset]);
+
+  ASSERT_GE(static_cast<unsigned char>(kV8LatestKnownVersion),
+            wireData[kSSVHeaderV8VersionOffset]);
+  ASSERT_EQ(static_cast<unsigned char>(VersionTag),
+            wireData[kSSVHeaderV8VersionTagOffset]);
+}
+
+PassRefPtr<IDBValue> createIDBValue(v8::Isolate* isolate,
+                                    Vector<char>& wireBytes,
+                                    double primaryKey,
+                                    const WebString& keyPath) {
+  WebData webData(SharedBuffer::adoptVector(wireBytes));
+  Vector<WebBlobInfo> webBlobInfo;
+  WebIDBKey webIdbKey = WebIDBKey::createNumber(primaryKey);
+  WebIDBKeyPath webIdbKeyPath(keyPath);
+  WebIDBValue webIdbValue(webData, webBlobInfo, webIdbKey, webIdbKeyPath);
+  return IDBValue::create(webIdbValue, isolate);
+}
+
 TEST(IDBKeyFromValueAndKeyPathTest, TopLevelPropertyStringValue) {
   V8TestingScope scope;
   v8::Isolate* isolate = scope.isolate();
@@ -238,4 +305,89 @@ TEST(InjectIDBKeyTest, SubProperty) {
                  scriptObject, "foo.xyz.foo");
 }
 
+TEST(DeserializeIDBValueTest, CurrentVersions) {
+  V8TestingScope scope;
+  v8::Isolate* isolate = scope.isolate();
+
+  Vector<char> objectBytes;
+  v8::Local<v8::Object> emptyObject = v8::Object::New(isolate);
+  serializeV8Value(emptyObject, isolate, &objectBytes);
+  RefPtr<IDBValue> idbValue = createIDBValue(isolate, objectBytes, 42.0, "foo");
+
+  v8::Local<v8::Value> v8Value =
+      deserializeIDBValue(isolate, scope.context()->Global(), idbValue.get());
+  EXPECT_TRUE(!scope.getExceptionState().hadException());
+
+  ASSERT_TRUE(v8Value->IsObject());
+  v8::Local<v8::Object> v8ValueObject = v8Value.As<v8::Object>();
+  v8::Local<v8::Value> v8NumberValue =
+      v8ValueObject->Get(scope.context(), v8AtomicString(isolate, "foo"))
+          .ToLocalChecked();
+  ASSERT_TRUE(v8NumberValue->IsNumber());
+  v8::Local<v8::Number> v8Number = v8NumberValue.As<v8::Number>();
+  EXPECT_EQ(v8Number->Value(), 42.0);
+}
+
+TEST(DeserializeIDBValueTest, FutureV8Version) {
+  V8TestingScope scope;
+  v8::Isolate* isolate = scope.isolate();
+
+  // Pretend that the object was serialized by a future version of V8.
+  Vector<char> objectBytes;
+  v8::Local<v8::Object> emptyObject = v8::Object::New(isolate);
+  serializeV8Value(emptyObject, isolate, &objectBytes);
+  objectBytes[kSSVHeaderV8VersionTagOffset] += 1;
+
+  // The call sequence below mimics IndexedDB's usage pattern when attempting to
+  // read a value in an object store with a key generator and a key path, but
+  // the serialized value uses a newer format version.
+  //
+  // http://crbug.com/703704 has a reproduction for this test's circumstances.
+  RefPtr<IDBValue> idbValue = createIDBValue(isolate, objectBytes, 42.0, "foo");
+
+  v8::Local<v8::Value> v8Value =
+      deserializeIDBValue(isolate, scope.context()->Global(), idbValue.get());
+  EXPECT_TRUE(!scope.getExceptionState().hadException());
+  EXPECT_TRUE(v8Value->IsNull());
+}
+
+TEST(DeserializeIDBValueTest, InjectionIntoNonObject) {
+  V8TestingScope scope;
+  v8::Isolate* isolate = scope.isolate();
+
+  // Simulate a storage corruption where an object is read back as a number.
+  // This test uses a one-segment key path.
+  Vector<char> objectBytes;
+  v8::Local<v8::Number> number = v8::Number::New(isolate, 42.0);
+  serializeV8Value(number, isolate, &objectBytes);
+  RefPtr<IDBValue> idbValue = createIDBValue(isolate, objectBytes, 42.0, "foo");
+
+  v8::Local<v8::Value> v8Value =
+      deserializeIDBValue(isolate, scope.context()->Global(), idbValue.get());
+  EXPECT_TRUE(!scope.getExceptionState().hadException());
+  ASSERT_TRUE(v8Value->IsNumber());
+  v8::Local<v8::Number> v8Number = v8Value.As<v8::Number>();
+  EXPECT_EQ(v8Number->Value(), 42.0);
+}
+
+TEST(DeserializeIDBValueTest, NestedInjectionIntoNonObject) {
+  V8TestingScope scope;
+  v8::Isolate* isolate = scope.isolate();
+
+  // Simulate a storage corruption where an object is read back as a number.
+  // This test uses a multiple-segment key path.
+  Vector<char> objectBytes;
+  v8::Local<v8::Number> number = v8::Number::New(isolate, 42.0);
+  serializeV8Value(number, isolate, &objectBytes);
+  RefPtr<IDBValue> idbValue =
+      createIDBValue(isolate, objectBytes, 42.0, "foo.bar");
+
+  v8::Local<v8::Value> v8Value =
+      deserializeIDBValue(isolate, scope.context()->Global(), idbValue.get());
+  EXPECT_TRUE(!scope.getExceptionState().hadException());
+  ASSERT_TRUE(v8Value->IsNumber());
+  v8::Local<v8::Number> v8Number = v8Value.As<v8::Number>();
+  EXPECT_EQ(v8Number->Value(), 42.0);
+}
+
 }  // namespace blink