Bug 1018320 - RequestSync API - patch 7 - reject promise when an exception is thrown, r=fabrice

dom/messages/SystemMessageInternal.js

@@ -470,7 +470,7 @@ SystemMessageInternal.prototype = {
                                          true,
                                          null);
 
-          this._rejectPendingPromises(manifestURL);
+          this._rejectPendingPromisesFromManifestURL(manifestURL);
         }
         break;
       }
@@ -482,7 +482,7 @@ SystemMessageInternal.prototype = {
                                        msg.manifestURL,
                                        false,
                                        msg.pageURL);
-        this._rejectPendingPromises(msg.manifestURL);
+        this._rejectPendingPromisesFromManifestURL(msg.manifestURL);
         break;
       }
       case "SystemMessageManager:GetPendingMessages":
@@ -554,10 +554,14 @@ SystemMessageInternal.prototype = {
       {
         debug("received SystemMessageManager:HandleMessageDone " + msg.type +
           " with msgID " + msg.msgID + " for " + msg.pageURL +
-          " @ " + msg.manifestURL);
+          " @ " + msg.manifestURL + " - promise rejected: " + msg.rejected);
 
-        // Maybe this should resolve a pending promise.
-        this._resolvePendingPromises(msg.msgID);
+        // Maybe this should resolve/reject a pending promise.
+        if (msg.rejected) {
+          this._rejectPendingPromises(msg.msgID);
+        } else {
+          this._resolvePendingPromises(msg.msgID);
+        }
 
         // A page has finished handling some of its system messages, so we try
         // to release the CPU wake lock we acquired on behalf of that page.
@@ -644,7 +648,7 @@ SystemMessageInternal.prototype = {
           }
         }
 
-        this._rejectPendingPromises(manifestURL);
+        this._rejectPendingPromisesFromManifestURL(manifestURL);
 
         debug("Finish updating registered pages for an uninstalled app.");
         break;
@@ -789,7 +793,20 @@ SystemMessageInternal.prototype = {
     }
   },
 
-  _rejectPendingPromises: function(aManifestURL) {
+  _rejectPendingPromises: function(aMessageID) {
+    if (!this._pendingPromises.has(aMessageID)) {
+      debug("Unknown pendingPromise messageID. This seems a bug!!");
+      return;
+    }
+
+    let obj = this._pendingPromises.get(aMessageID);
+    if (!--obj.counter) {
+      obj.rejectPromiseCb();
+      this._pendingPromises.delete(aMessageID);
+    }
+  },
+
+  _rejectPendingPromisesFromManifestURL: function(aManifestURL) {
     for (var [i, obj] of this._pendingPromises) {
       if (obj.manifestURL == aManifestURL) {
         obj.rejectPromiseCb();

dom/messages/SystemMessageManager.js

@@ -95,9 +95,14 @@ SystemMessageManager.prototype = {
       }
     }
 
-    aDispatcher.handler
-      .handleMessage(wrapped ? aMessage
-                             : Cu.cloneInto(aMessage, this._window));
+    let message = wrapped ? aMessage : Cu.cloneInto(aMessage, this._window);
+
+    let rejectPromise = false;
+    try {
+      aDispatcher.handler.handleMessage(message);
+    } catch(e) {
+      rejectPromise = true;
+    }
 
     this._isHandling = false;
     aDispatcher.isHandling = false;
@@ -111,7 +116,8 @@ SystemMessageManager.prototype = {
                             { type: aType,
                               manifestURL: self._manifestURL,
                               pageURL: self._pageURL,
-                              msgID: aMessageID });
+                              msgID: aMessageID,
+                              rejected: rejectPromise });
     }
 
     if (!this._promise) {
@@ -119,7 +125,10 @@ SystemMessageManager.prototype = {
       sendResponse();
     } else {
       debug("Using the promise to postpone the response.");
-      this._promise.then(sendResponse, sendResponse);
+      this._promise.then(sendResponse, function() {
+        rejectPromise = true;
+        sendResponse();
+      });
       this._promise = null;
     }
 

dom/requestsync/RequestSyncService.jsm

@@ -678,6 +678,7 @@ this.RequestSyncService = {
     }, timeout, Ci.nsITimer.TYPE_ONE_SHOT);
 
     // Sending the message.
+    debug("Sending message.");
     let promise =
       systemMessenger.sendMessage('request-sync',
                                   this.createPartialTaskObject(aObj.data),

dom/requestsync/tests/test_wakeUp.html

@@ -15,7 +15,7 @@
   var multiShotCounter = 0;
 
   function maybeDone() {
-    if (oneShotCounter == 1 && multiShotCounter == 3) {
+    if (oneShotCounter == 1 && multiShotCounter == 5) {
       runTests();
     }
   }
@@ -57,7 +57,18 @@
           }));
         } else if (multiShotCounter == 2) {
           // The second time we don't reply at all.
+          info("Setting a promise object without resolving it.");
           navigator.mozSetMessageHandlerPromise(new Promise(function(a, b) {}));
+        } else if (multiShotCounter == 3) {
+          info("Throwing an exception.");
+          // Now we throw an exception
+          SimpleTest.expectUncaughtException();
+          throw "Booom!";
+        } else {
+          info("Setting a promise object and reject it.");
+          navigator.mozSetMessageHandlerPromise(new Promise(function(a, b) {
+            setTimeout(b, 0);
+          }));
         }
 
         maybeDone();