Fix start-time functionality in the video player.

When there is a start-time:

Initially, the video starts playing from the start-time.
Whenever the player resets for any reason (such as reaching
the end of the video), it will reset to start-time instead of 00:00:00.
It should not be the case that any time the user presses play, it
start playing from start-time.

BLD-659.

common/lib/xmodule/xmodule/js/spec/video/general_spec.js

@@ -221,7 +221,7 @@
                 expect(state.videoPlayer.play).toHaveBeenCalled();
             });
 
-            it('when cued, onEnded resets start and end time only the second time', function () {
+            it('even when cued, onEnded does not resets start and end time', function () {
                 state.videoPlayer.skipOnEndedStartEndReset = true;
                 state.videoPlayer.onEnded();
                 expect(state.videoPlayer.startTime).toBe(10);
@@ -229,8 +229,8 @@
 
                 state.videoPlayer.skipOnEndedStartEndReset = undefined;
                 state.videoPlayer.onEnded();
-                expect(state.videoPlayer.startTime).toBe(0);
-                expect(state.videoPlayer.endTime).toBe(null);
+                expect(state.videoPlayer.startTime).toBe(10);
+                expect(state.videoPlayer.endTime).toBe(30);
             });
         });
 

common/lib/xmodule/xmodule/js/spec/video/video_player_spec.js

@@ -562,6 +562,7 @@ function (VideoPlayer) {
                 runs(function () {
                     var htmlStr;
 
+                    state.videoPlayer.goToStartTime = false;
                     state.videoPlayer.updatePlayTime(60);
 
                     htmlStr = $('.vidtime').html();
@@ -589,6 +590,7 @@ function (VideoPlayer) {
                 }, 'Video is fully loaded.', WAIT_TIMEOUT);
 
                 runs(function () {
+                    state.videoPlayer.goToStartTime = false;
                     state.videoPlayer.updatePlayTime(60);
 
                     expect(state.videoCaption.updatePlayTime)
@@ -606,6 +608,7 @@ function (VideoPlayer) {
                 }, 'Video is fully loaded.', WAIT_TIMEOUT);
 
                 runs(function () {
+                    state.videoPlayer.goToStartTime = false;
                     state.videoPlayer.updatePlayTime(60);
 
                     expect(state.videoProgressSlider.updatePlayTime)
@@ -677,35 +680,39 @@ function (VideoPlayer) {
 
         describe('updatePlayTime with invalid endTime', function () {
             beforeEach(function () {
-                state = jasmine.initializePlayer(
-                    {
-                        end: 100000
-                    }
-                );
-
-                state.videoEl = $('video, iframe');
-
-                spyOn(state.videoPlayer, 'updatePlayTime').andCallThrough();
+                state = {
+                    videoPlayer: {
+                        duration: function () {
+                            // The video will be 60 seconds long.
+                            return 60;
+                        },
+                        goToStartTime: true,
+                        startTime: undefined,
+                        endTime: undefined,
+                        player: {
+                            seekTo: function () {}
+                        }
+                    },
+                    config: {
+                        savedVideoPosition: 0,
+                        startTime: 0,
+
+                        // We are setting the end-time to 10000 seconds. The
+                        // video will be less than this, the code will reset
+                        // the end time to `null` - i.e. to the end of the video.
+                        // This is the expected behavior we will test for.
+                        endTime: 10000
+                    },
+                    currentPlayerMode: 'html5',
+                    trigger: function () {},
+                    browserIsFirefox: false
+                };
             });
 
             it('invalid endTime is reset to null', function () {
-                var duration;
+                VideoPlayer.prototype.updatePlayTime.call(state, 0);
 
-                state.videoPlayer.updatePlayTime.reset();
-                state.videoPlayer.play();
-
-                waitsFor(
-                    function () {
-                        return state.videoPlayer.isPlaying() &&
-                            state.videoPlayer.initialSeekToStartTime === false;
-                    },
-                    'updatePlayTime was invoked and duration is set',
-                    WAIT_TIMEOUT
-                );
-
-                runs(function () {
-                    expect(state.videoPlayer.endTime).toBe(null);
-                });
+                expect(state.videoPlayer.endTime).toBe(null);
             });
         });
 

common/lib/xmodule/xmodule/js/src/video/06_video_progress_slider.js

@@ -180,6 +180,10 @@ function () {
     function onSlide(event, ui) {
         this.videoProgressSlider.frozen = true;
 
+        // Remember the seek to value so that we don't repeat ourselves on the
+        // 'stop' slider event.
+        this.videoProgressSlider.lastSeekValue = ui.value;
+
         this.trigger(
             'videoPlayer.onSlideSeek',
             {'type': 'onSlideSeek', 'time': ui.value}
@@ -196,10 +200,16 @@ function () {
 
         this.videoProgressSlider.frozen = true;
 
-        this.trigger(
-            'videoPlayer.onSlideSeek',
-            {'type': 'onSlideSeek', 'time': ui.value}
-        );
+        // Only perform a seek if we haven't made a seek for the new slider value.
+        // This is necessary so that if the user only clicks on the slider, without
+        // dragging it, then only one seek is made, even when a 'slide' and a 'stop'
+        // events are triggered on the slider.
+        if (this.videoProgressSlider.lastSeekValue !== ui.value) {
+            this.trigger(
+                'videoPlayer.onSlideSeek',
+                {'type': 'onSlideSeek', 'time': ui.value}
+            );
+        }
 
         // ARIA
         this.videoProgressSlider.handle.attr(
@@ -216,8 +226,8 @@ function () {
             duration = Math.floor(params.duration);
 
         if (
-            (this.videoProgressSlider.slider) &&
-            (!this.videoProgressSlider.frozen)
+            this.videoProgressSlider.slider &&
+            !this.videoProgressSlider.frozen
         ) {
             this.videoProgressSlider.slider
                 .slider('option', 'max', duration)