fix: auto cancel trickPlay on live as specified (#6100)

Fixes #5944

Backported to v4.3.x

lib/player.js

@@ -479,6 +479,12 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
      */
     this.loadEventManager_ = new shaka.util.EventManager();
 
+    /**
+     * For listeners scoped to the lifetime of the loaded content.
+     * @private {shaka.util.EventManager}
+     */
+    this.trickPlayEventManager_ = new shaka.util.EventManager();
+
     /** @private {shaka.net.NetworkingEngine} */
     this.networkingEngine_ = null;
 
@@ -897,6 +903,10 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       this.loadEventManager_.release();
       this.loadEventManager_ = null;
     }
+    if (this.trickPlayEventManager_) {
+      this.trickPlayEventManager_.release();
+      this.trickPlayEventManager_ = null;
+    }
 
     this.abrManagerFactory_ = null;
     this.config_ = null;
@@ -1555,6 +1565,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
     // be if there was an error and we, by chance, did not have a media element.
     if (has.mediaElement) {
       this.loadEventManager_.removeAll();
+      this.trickPlayEventManager_.removeAll();
     }
 
     // Stop the variant checker timer
@@ -3709,6 +3720,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       shaka.log.alwaysWarn('A trick play rate of 0 is unsupported!');
       return;
     }
+    this.trickPlayEventManager_.removeAll();
 
     if (this.video_.paused) {
       // Our fast forward is implemented with playbackRate and needs the video
@@ -3722,6 +3734,22 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       this.abrManager_.playbackRateChanged(rate);
       this.streamingEngine_.setTrickPlay(Math.abs(rate) > 1);
     }
+    if (this.isLive()) {
+      this.trickPlayEventManager_.listen(this.video_, 'timeupdate', () => {
+        const currentTime = this.video_.currentTime;
+        const seekRange = this.seekRange();
+        const safeSeekOffset = this.config_.streaming.safeSeekOffset;
+        if (rate > 0) {
+          if (currentTime >= seekRange.end) {
+            this.cancelTrickPlay();
+          }
+        } else {
+          if (currentTime <= (seekRange.start + safeSeekOffset)) {
+            this.cancelTrickPlay();
+          }
+        }
+      });
+    }
   }
 
   /**
@@ -3741,6 +3769,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       this.abrManager_.playbackRateChanged(defaultPlaybackRate);
       this.streamingEngine_.setTrickPlay(false);
     }
+    this.trickPlayEventManager_.removeAll();
   }
 
   /**