IndexedDB: Disallow continuePrimaryKey on unique cursors

Source/modules/indexeddb/IDBCursor.cpp

 /*
  * Copyright (C) 2010 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 148 matching lines @@
     continueFunction(key, nullptr, exceptionState);
 }
 
 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;
     }
+    if (m_direction != WebIDBCursorDirectionNext && m_direction != WebIDBCursorDirectionPrev) {
+        exceptionState.throwDOMException(InvalidAccessError, "The cursor's direction is not 'next' or 'prev'.");
+        return;
+    }
 
     IDBKey* key = ScriptValue::to<IDBKey*>(scriptState->isolate(), keyValue, exceptionState);
     if (exceptionState.hadException())
         return;
     if (!key->isValid()) {
         exceptionState.throwDOMException(DataError, IDBDatabase::notValidKeyErrorMessage);
         return;
     }
 
     IDBKey* primaryKey = ScriptValue::to<IDBKey*>(scriptState->isolate(), primaryKeyValue, exceptionState);
@@ skipping 210 matching lines @@
     case WebIDBCursorDirectionPrevNoDuplicate:
         return IndexedDBNames::prevunique;
 
     default:
         ASSERT_NOT_REACHED();
         return IndexedDBNames::next;
     }
 }
 
 } // namespace blink