Bug 1919555 - LSNG: Error out LSObject::EnsureDatabase if preparation has been invalidated; r=dom-storage-reviewers,nika,asuth

Differential Revision: https://phabricator.services.mozilla.com/D222425

dom/localstorage/ActorsParent.cpp

@@ -7539,6 +7539,7 @@ void PrepareDatastoreOp::GetResponse(LSRequestResponse& aResponse) {
       LSRequestPrepareDatastoreResponse prepareDatastoreResponse;
       prepareDatastoreResponse.databaseChildEndpoint() =
           std::move(childEndpoint);
+      prepareDatastoreResponse.invalidated() = mInvalidated;
 
       aResponse = std::move(prepareDatastoreResponse);
     }

dom/localstorage/LSObject.cpp

@@ -946,6 +946,11 @@ nsresult LSObject::EnsureDatabase() {
   glean::ls_preparelsdatabase::processing_time.StopAndAccumulate(
       std::move(latencyTimerId));
 
+  if (prepareDatastoreResponse.invalidated()) {
+    database->RequestAllowToClose();
+    return NS_ERROR_ABORT;
+  }
+
   mDatabase = std::move(database);
 
   return NS_OK;

dom/localstorage/PBackgroundLSRequest.ipdl

@@ -18,6 +18,7 @@ struct LSRequestPreloadDatastoreResponse
 struct LSRequestPrepareDatastoreResponse
 {
   Endpoint<PBackgroundLSDatabaseChild> databaseChildEndpoint;
+  bool invalidated;
 };
 
 struct LSRequestPrepareObserverResponse

dom/localstorage/test/unit/slowDatabaseInitialization_child.js

@@ -16,6 +16,11 @@ add_task(async function testSteps() {
 
   const storage = LocalStorageUtils.createStorage(principal);
 
-  // XXX This should throw!
-  storage.getItem("foo");
+  try {
+    storage.getItem("foo");
+    ok(false, "Should have thrown");
+  } catch (e) {
+    ok(true, "Should have thrown");
+    Assert.strictEqual(e.result, Cr.NS_ERROR_ABORT, "Threw right result code");
+  }
 });