From 0aee684c1794ea09534b41ad0dacb1f897158790 Mon Sep 17 00:00:00 2001
From: Tim Taubert <ttaubert@mozilla.com>
Date: Fri, 28 Jul 2017 15:53:42 +0200
Subject: [PATCH] Bug 1385274 - Don't try to resolve
 WebAuthnManager::mPBackgroundCreationPromise twice r=jcj

---
 dom/webauthn/WebAuthnManager.cpp | 26 +++++++++++++++++++++-----
 dom/webauthn/WebAuthnManager.h   |  7 ++++---
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/dom/webauthn/WebAuthnManager.cpp b/dom/webauthn/WebAuthnManager.cpp
index 4ad009afcb10..835680225579 100644
--- a/dom/webauthn/WebAuthnManager.cpp
+++ b/dom/webauthn/WebAuthnManager.cpp
@@ -239,14 +239,25 @@ WebAuthnManager::~WebAuthnManager()
   MaybeClearTransaction();
 }
 
-already_AddRefed<MozPromise<nsresult, nsresult, false>>
+RefPtr<WebAuthnManager::BackgroundActorPromise>
 WebAuthnManager::GetOrCreateBackgroundActor()
 {
-  bool ok = BackgroundChild::GetOrCreateForCurrentThread(this);
-  if (NS_WARN_IF(!ok)) {
-    ActorFailed();
+  MOZ_ASSERT(NS_IsMainThread());
+
+  PBackgroundChild *actor = BackgroundChild::GetForCurrentThread();
+  RefPtr<WebAuthnManager::BackgroundActorPromise> promise =
+    mPBackgroundCreationPromise.Ensure(__func__);
+
+  if (actor) {
+    ActorCreated(actor);
+  } else {
+    bool ok = BackgroundChild::GetOrCreateForCurrentThread(this);
+    if (NS_WARN_IF(!ok)) {
+      ActorFailed();
+    }
   }
-  return mPBackgroundCreationPromise.Ensure(__func__);
+
+  return promise;
 }
 
 //static
@@ -875,8 +886,13 @@ WebAuthnManager::Cancel(const nsresult& aError)
 void
 WebAuthnManager::ActorCreated(PBackgroundChild* aActor)
 {
+  MOZ_ASSERT(NS_IsMainThread());
   MOZ_ASSERT(aActor);
 
+  if (mChild) {
+    return;
+  }
+
   RefPtr<WebAuthnTransactionChild> mgr(new WebAuthnTransactionChild());
   PWebAuthnTransactionChild* constructedMgr =
     aActor->SendPWebAuthnTransactionConstructor(mgr);
diff --git a/dom/webauthn/WebAuthnManager.h b/dom/webauthn/WebAuthnManager.h
index 730d954ab5b4..8e832742d70d 100644
--- a/dom/webauthn/WebAuthnManager.h
+++ b/dom/webauthn/WebAuthnManager.h
@@ -99,8 +99,9 @@ private:
 
   void MaybeClearTransaction();
 
-  already_AddRefed<MozPromise<nsresult, nsresult, false>>
-  GetOrCreateBackgroundActor();
+  typedef MozPromise<nsresult, nsresult, false> BackgroundActorPromise;
+
+  RefPtr<BackgroundActorPromise> GetOrCreateBackgroundActor();
 
   // JS Promise representing transaction status.
   RefPtr<Promise> mTransactionPromise;
@@ -120,7 +121,7 @@ private:
   Maybe<WebAuthnTransactionInfo> mInfo;
 
   // Promise for dealing with PBackground Actor creation.
-  MozPromiseHolder<MozPromise<nsresult, nsresult, false>> mPBackgroundCreationPromise;
+  MozPromiseHolder<BackgroundActorPromise> mPBackgroundCreationPromise;
 };
 
 } // namespace dom