IndexedDB: continuePrimaryKey() on object store cursor should throw

Source/modules/indexeddb/IDBCursor.cpp

Index: Source/modules/indexeddb/IDBCursor.cpp
diff --git a/Source/modules/indexeddb/IDBCursor.cpp b/Source/modules/indexeddb/IDBCursor.cpp
index 8ec7e528b4bc5d8b32b786f4f497d8ceb3cd05a6..6385679fad0352761f878aec17e4441d8e30e23a 100644
--- a/Source/modules/indexeddb/IDBCursor.cpp
+++ b/Source/modules/indexeddb/IDBCursor.cpp
@@ -160,6 +160,11 @@ void IDBCursor::continueFunction(ScriptState* scriptState, const ScriptValue& ke
 void IDBCursor::continuePrimaryKey(ScriptState* scriptState, const ScriptValue& keyValue, const ScriptValue& primaryKeyValue, ExceptionState& exceptionState)
 {
     IDB_TRACE("IDBCursor::continuePrimaryKey");
+    if (m_source->type() != IDBAny::IDBIndexType) {
+        exceptionState.throwDOMException(InvalidAccessError, "The cursor's source is not an index.");
+        return;
+    }
+
     IDBKey* key = ScriptValue::to<IDBKey*>(scriptState->isolate(), keyValue, exceptionState);
     IDBKey* primaryKey = ScriptValue::to<IDBKey*>(scriptState->isolate(), primaryKeyValue, exceptionState);
     if (!key->isValid() || !primaryKey->isValid()) {