From ccca846da8766a03274dc8b537a90891a3dc33a8 Mon Sep 17 00:00:00 2001
From: Grzegorz Blaszczyk <grzegorz.blaszczyk@screen9.com>
Date: Fri, 15 Nov 2019 19:44:34 +0100
Subject: [PATCH] feat: resets pastSeekEnd_ variable. (#6249)

* feat: resets pastSeekEnd_ when its value is much higher than seeking increment.

* fixes unit tests
---
 src/js/live-tracker.js         | 8 +++++++-
 test/unit/live-tracker.test.js | 8 ++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/js/live-tracker.js b/src/js/live-tracker.js
index 3463ff4079..13d684a0d2 100644
--- a/src/js/live-tracker.js
+++ b/src/js/live-tracker.js
@@ -88,7 +88,13 @@ class LiveTracker extends Component {
       this.trigger('seekableendchange');
     }
 
-    this.pastSeekEnd_ = this.pastSeekEnd() + 0.03;
+    // we should reset pastSeekEnd when the value
+    // is much higher than seeking increment.
+    if (this.pastSeekEnd() > this.seekableIncrement_ * 1.5) {
+      this.pastSeekEnd_ = 0;
+    } else {
+      this.pastSeekEnd_ = this.pastSeekEnd() + 0.03;
+    }
 
     if (this.isBehind_() !== this.behindLiveEdge()) {
       this.behindLiveEdge_ = this.isBehind_();
diff --git a/test/unit/live-tracker.test.js b/test/unit/live-tracker.test.js
index ac69e437bf..a0f42af0fc 100644
--- a/test/unit/live-tracker.test.js
+++ b/test/unit/live-tracker.test.js
@@ -68,9 +68,12 @@ QUnit.module('LiveTracker', () => {
   QUnit.test('Triggers liveedgechange when we fall behind and catch up', function(assert) {
 
     this.liveTracker.seekableIncrement_ = 6;
+    this.player.seekable = () => createTimeRanges(0, 20);
     this.player.trigger('timeupdate');
-    this.player.currentTime = () => 0;
-    this.clock.tick(20000);
+    this.player.currentTime = () => 14;
+    this.clock.tick(6000);
+    this.player.seekable = () => createTimeRanges(0, 26);
+    this.clock.tick(1000);
 
     assert.equal(this.liveEdgeChanges, 1, 'should have one live edge change');
     assert.ok(this.liveTracker.behindLiveEdge(), 'behind live edge');
@@ -99,6 +102,7 @@ QUnit.module('LiveTracker', () => {
   QUnit.test('seeks to live edge on seekableendchange', function(assert) {
     this.player.trigger('timeupdate');
 
+    this.player.seekable = () => createTimeRanges(0, 6);
     this.liveTracker.seekableIncrement_ = 2;
     let currentTime = 0;