Fire window.onerror for uncaught IndexedDB errors

Source/modules/indexeddb/IDBRequest.cpp

Index: Source/modules/indexeddb/IDBRequest.cpp
diff --git a/Source/modules/indexeddb/IDBRequest.cpp b/Source/modules/indexeddb/IDBRequest.cpp
index 16992b32ade0174816e1f35db0e4ff8a6bd849fd..7f99e1d97a4222dcbb03bcbee6dae83a0fb6c6a1 100644
--- a/Source/modules/indexeddb/IDBRequest.cpp
+++ b/Source/modules/indexeddb/IDBRequest.cpp
@@ -31,9 +31,13 @@
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
+#include "bindings/core/v8/ScriptCallStackFactory.h"
 #include "bindings/modules/v8/IDBBindingUtilities.h"
 #include "core/dom/ExecutionContext.h"
+#include "core/events/ErrorEvent.h"
 #include "core/events/EventQueue.h"
+#include "core/inspector/ScriptCallFrame.h"
+#include "core/inspector/ScriptCallStack.h"
 #include "modules/indexeddb/IDBCursorWithValue.h"
 #include "modules/indexeddb/IDBDatabase.h"
 #include "modules/indexeddb/IDBEventDispatcher.h"
@@ -72,6 +76,9 @@ IDBRequest::IDBRequest(ScriptState* scriptState, IDBAny* source, IDBTransaction*
     , m_resultDirty(true)
 {
     ScriptWrappable::init(this);
+
+    m_creationStackTrace = createScriptCallStack(ScriptCallStack::maxCallStackSizeToCapture, false);

[aandrey, 2014/07/08 18:40:16]

Probably we should collect the stacks only when DevTools is open. We don't
collect stacks in other places (like if exception is thrown) in Blink as well as
in V8 unless DevTools is open.

Also this looks very similar to the Promise uncaught async exception issue:
https://code.google.com/p/v8/issues/detail?id=3093

For example, is there the same issue with this async exception, as to whether
it's actually "uncaught" or not at the time it's fired. One could attach a
req.onerror handler later asynchronously, and probably this handler should be
invoked instead of window.onerror.

+    ASSERT(m_creationStackTrace && m_creationStackTrace->size());
 }
 
 IDBRequest::~IDBRequest()
@@ -92,6 +99,7 @@ void IDBRequest::trace(Visitor* visitor)
     visitor->trace(m_pendingCursor);
     visitor->trace(m_cursorKey);
     visitor->trace(m_cursorPrimaryKey);
+    visitor->trace(m_creationStackTrace);
     EventTargetWithInlineData::trace(visitor);
 }
 
@@ -493,6 +501,20 @@ bool IDBRequest::dispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
     if (m_readyState == DONE && event->type() != EventTypeNames::upgradeneeded)
         m_hasPendingActivity = false;
 
+    // Fire window.onerror (or the equivalent for workers) for errors that were not prevented.
+    if (!m_preventPropagation && dontPreventDefault && event->type() == EventTypeNames::error) {
+        const ScriptCallFrame& frame = m_creationStackTrace->at(0);
+        const AccessControlStatus corsStatus = NotSharableCrossOrigin;
+        RefPtrWillBeRawPtr<ErrorEvent> errorEvent;
+        if (executionContext()->shouldSanitizeScriptError(frame.sourceURL(), corsStatus)) {
+            errorEvent = ErrorEvent::createSanitizedError(&m_scriptState->world());
+        } else {
+            String message = m_error->name() + ": " + m_error->message();
+            errorEvent = ErrorEvent::create(message, frame.sourceURL(), frame.lineNumber(), frame.columnNumber(), &m_scriptState->world());
+        }
+        executionContext()->reportException(errorEvent, m_creationStackTrace, corsStatus);
+    }
+
     return dontPreventDefault;
 }