Graceful handling of new versions of IndexedDB serialized data.

third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp

Index: third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp
diff --git a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp
index f2a8be4e39a38c7f30aafb55075aec6c9dd5f064..a8ef6189e2196ee21dc12aa38420120d348559fc 100644
--- a/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp
+++ b/third_party/WebKit/Source/bindings/modules/v8/V8BindingForModules.cpp
@@ -57,10 +57,6 @@ namespace blink {
 
 static v8::Local<v8::Value> deserializeIDBValueData(v8::Isolate*,
                                                     const IDBValue*);
-static v8::Local<v8::Value> deserializeIDBValue(
-    v8::Isolate*,
-    v8::Local<v8::Object> creationContext,
-    const IDBValue*);
 static v8::Local<v8::Value> deserializeIDBValueArray(
     v8::Isolate*,
     v8::Local<v8::Object> creationContext,
@@ -394,16 +390,21 @@ static v8::Local<v8::Value> deserializeIDBValueData(v8::Isolate* isolate,
 }
 
 // Deserialize the entire IDBValue (injecting key & keypath if present).
-static v8::Local<v8::Value> deserializeIDBValue(
-    v8::Isolate* isolate,
-    v8::Local<v8::Object> creationContext,
-    const IDBValue* value) {
+v8::Local<v8::Value> deserializeIDBValue(v8::Isolate* isolate,
+                                         v8::Local<v8::Object> creationContext,
+                                         const IDBValue* value) {
   ASSERT(isolate->InContext());
   if (!value || value->isNull())
     return v8::Null(isolate);
 
   v8::Local<v8::Value> v8Value = deserializeIDBValueData(isolate, value);
-  if (value->primaryKey()) {
+
+  // De-serialization failures are currently handled by returning null. This is
+  // sub-optimal, as it can cause IndexedDB to return incorrect data. The check
+  // below is the minimal work needed to avoid a crash. A proper solution would
+  // require SerializedScriptValue to throw rather than returning null when it
+  // encounters errors.
+  if (value->primaryKey() && !v8Value->IsNull()) {
     v8::Local<v8::Value> key =
         ToV8(value->primaryKey(), creationContext, isolate);
     if (key.IsEmpty())