Indexed DB: Prevent inspector from re-creating deleted databases

third_party/WebKit/Source/modules/indexeddb/InspectorIndexedDBAgent.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 176 matching lines @@
         idbDatabase->close();
     }
 
 private:
     OpenDatabaseCallback(ExecutableWithDatabase* executableWithDatabase)
         : EventListener(EventListener::CPPEventListenerType)
         , m_executableWithDatabase(executableWithDatabase) { }
     RefPtr<ExecutableWithDatabase> m_executableWithDatabase;
 };
 
+class UpgradeDatabaseCallback final : public EventListener {
+public:
+    static PassRefPtrWillBeRawPtr<UpgradeDatabaseCallback> create(ExecutableWithDatabase* executableWithDatabase)
+    {
+        return adoptRefWillBeNoop(new UpgradeDatabaseCallback(executableWithDatabase));
+    }
+
+    ~UpgradeDatabaseCallback() override { }
+
+    bool operator==(const EventListener& other) override
+    {
+        return this == &other;
+    }
+
+    void handleEvent(ExecutionContext* context, Event* event) override
+    {
+        if (event->type() != EventTypeNames::upgradeneeded) {

[cmumford, 2015/10/22 16:10:43]

Why not just an ASSERT for this as we're only observing this one type?

[jsbell, 2015/10/22 19:57:31]

I'm leaving this as-is (copy/pasta from other handlers); I believe the intent is
just to be resilient in case the spec changes and the inspector wasn't adapted.
(Script can also generate/dispatch events, but script should also never see
these requests or we have a world isolation bug.)

If we want to change to an ASSERT we should change them all.

+            m_executableWithDatabase->requestCallback()->sendFailure("Unexpected event type.");
+            return;
+        }
+
+        // If an "upgradeneeded" event comes through then the database that
+        // had previously been enumerate was deleted. We don't want to

[cmumford, 2015/10/22 16:10:43]

s/enumerate/enumerated/

[jsbell, 2015/10/22 19:57:31]

Done.

+        // implicitly re-create it here, so abort the transaction.
+        IDBOpenDBRequest* idbOpenDBRequest = static_cast<IDBOpenDBRequest*>(event->target());
+        NonThrowableExceptionState exceptionState;
+        idbOpenDBRequest->transaction()->abort(exceptionState);
+    }
+
+private:
+    UpgradeDatabaseCallback(ExecutableWithDatabase* executableWithDatabase)
+        : EventListener(EventListener::CPPEventListenerType)
+        , m_executableWithDatabase(executableWithDatabase) { }
+    RefPtr<ExecutableWithDatabase> m_executableWithDatabase;
+};
+
 void ExecutableWithDatabase::start(IDBFactory* idbFactory, SecurityOrigin*, const String& databaseName)
 {
-    RefPtrWillBeRawPtr<OpenDatabaseCallback> callback = OpenDatabaseCallback::create(this);
+    RefPtrWillBeRawPtr<OpenDatabaseCallback> openCallback = OpenDatabaseCallback::create(this);
+    RefPtrWillBeRawPtr<UpgradeDatabaseCallback> upgradeCallback = UpgradeDatabaseCallback::create(this);
     TrackExceptionState exceptionState;
     IDBOpenDBRequest* idbOpenDBRequest = idbFactory->open(scriptState(), databaseName, exceptionState);
     if (exceptionState.hadException()) {
         requestCallback()->sendFailure("Could not open database.");
         return;
     }
-    idbOpenDBRequest->addEventListener(EventTypeNames::success, callback, false);
+    idbOpenDBRequest->addEventListener(EventTypeNames::success, openCallback, false);
+    idbOpenDBRequest->addEventListener(EventTypeNames::upgradeneeded, upgradeCallback, false);
 }
 
 static IDBTransaction* transactionForDatabase(ScriptState* scriptState, IDBDatabase* idbDatabase, const String& objectStoreName, const String& mode = IndexedDBNames::readonly)
 {
     TrackExceptionState exceptionState;
     StringOrStringSequenceOrDOMStringList scope;
     scope.setString(objectStoreName);
     IDBTransaction* idbTransaction = idbDatabase->transaction(scriptState, scope, mode, exceptionState);
     if (exceptionState.hadException())
         return nullptr;
@@ skipping 572 matching lines @@
     RefPtr<ClearObjectStore> clearObjectStore = ClearObjectStore::create(scriptState, objectStoreName, requestCallback);
     clearObjectStore->start(idbFactory, document->securityOrigin(), databaseName);
 }
 
 DEFINE_TRACE(InspectorIndexedDBAgent)
 {
     InspectorBaseAgent::trace(visitor);
 }
 
 } // namespace blink