Bug 1075290 - Prevent a race condition between turnScreenOff and turn…

…ScreenOn

apps/system/js/screen_manager.js

@@ -95,6 +95,7 @@ var ScreenManager = {
    * To track the reason caused screen off?
    */
   _screenOffBy: null,
+  _screenOffTimeout: 0,
 
   /*
    * Request wakelock during in_call state.
@@ -367,7 +368,8 @@ var ScreenManager = {
       self.screenEnabled = false;
       self._inTransition = false;
       self.screen.classList.add('screenoff');
-      setTimeout(function realScreenOff() {
+      clearTimeout(self._screenOffTimeout);
+      self._screenOffTimeout = setTimeout(function realScreenOff() {
         self.setScreenBrightness(0, true);
         // Sometimes the ScreenManager.screenEnabled and mozPower.screenEnabled
         // values are out of sync. Since the rest of the world relies only on
@@ -401,6 +403,7 @@ var ScreenManager = {
   },
 
   turnScreenOn: function scm_turnScreenOn(instant) {
+    clearTimeout(this._screenOffTimeout);
     if (this.screenEnabled) {
       if (this._inTransition) {
         // Cancel the dim out

apps/system/test/unit/screen_manager_test.js

@@ -424,6 +424,7 @@ suite('system/ScreenManager', function() {
     var stubSetIdle,
         stubRemoveListener,
         stubScnClassListAdd,
+        stubScnClassListRemove,
         stubScreen,
         stubFireEvent,
         stubUnlock,
@@ -433,7 +434,9 @@ suite('system/ScreenManager', function() {
       stubSetIdle = this.sinon.stub(ScreenManager, '_setIdleTimeout');
       stubRemoveListener = this.sinon.stub(window, 'removeEventListener');
       stubScnClassListAdd = this.sinon.stub();
-      stubScreen = {'classList': {'add': stubScnClassListAdd}};
+      stubScnClassListRemove = this.sinon.stub();
+      stubScreen = {'classList': {'add': stubScnClassListAdd,
+                    'remove': stubScnClassListRemove}};
       stubFireEvent = this.sinon.stub(ScreenManager, 'fireScreenChangeEvent');
       stubUnlock = this.sinon.stub();
       stubSetBrightness = this.sinon.stub(ScreenManager, 'setScreenBrightness');
@@ -464,6 +467,19 @@ suite('system/ScreenManager', function() {
       assert.isTrue(ScreenManager.fireScreenChangeEvent.called);
     });
 
+    test('turn off instantly then on again', function() {
+      ScreenManager.screenEnabled = true;
+      assert.isTrue(ScreenManager.turnScreenOff(true, 'powerkey'));
+      this.sinon.clock.tick(10);
+      assert.isTrue(ScreenManager.turnScreenOn(true));
+      this.sinon.clock.tick(10);
+      assert.isTrue(ScreenManager.screenEnabled);
+      assert.isTrue(MockMozPower.screenEnabled);
+      assert.isTrue(stubScnClassListAdd.calledWith('screenoff'));
+      assert.isTrue(stubScnClassListRemove.calledWith('screenoff'));
+      sinon.assert.callOrder(stubScnClassListAdd, stubScnClassListRemove);
+    });
+
     test('turn off screen wihout instant argument', function() {
       ScreenManager.screenEnabled = true;
       assert.isTrue(ScreenManager.turnScreenOff(false));