fix: keep minimum volume after unmuting above 0.1 (#4227)

If, when unmuting, the last volume is below 0.1, force it to be 0.1.

Fixes #4054.

src/js/control-bar/mute-toggle.js

@@ -57,7 +57,9 @@ class MuteToggle extends Button {
     const lastVolume = this.player_.lastVolume_();
 
     if (vol === 0) {
-      this.player_.volume(lastVolume);
+      const volumeToSet = lastVolume < 0.1 ? 0.1 : lastVolume;
+
+      this.player_.volume(volumeToSet);
       this.player_.muted(false);
     } else {
       this.player_.muted(this.player_.muted() ? false : true);

test/unit/controls.test.js

@@ -148,6 +148,20 @@ if (Html5.isSupported()) {
     assert.equal(player.muted(), false, 'muted is set to false');
   });
 
+  QUnit.test('Clicking MuteToggle when volume is 0, lastVolume is less than 0.1, and muted is true sets volume to 0.1 and muted to false', function(assert) {
+    const player = TestHelpers.makePlayer({ techOrder: ['html5'] });
+    const muteToggle = new MuteToggle(player);
+
+    player.volume(0);
+    player.muted(true);
+    player.lastVolume_(0.05);
+
+    muteToggle.handleClick();
+
+    assert.equal(player.volume(), 0.1, 'since lastVolume is less than 0.1, volume is set to 0.1');
+    assert.equal(player.muted(), false, 'muted is set to false');
+  });
+
   QUnit.test('ARIA value of VolumeBar should start at 100', function(assert) {
     const player = TestHelpers.makePlayer({ techOrder: ['html5'] });
     const volumeBar = new VolumeBar(player);
@@ -179,5 +193,4 @@ if (Html5.isSupported()) {
     assert.equal(player.muted(), true, 'Muted is true');
     assert.equal(volumeBar.el_.getAttribute('aria-valuenow'), 0, 'ARIA value of VolumeBar is 0');
   });
-
 }