fix: sourceset and browser behavior inconsistencies (#5054)

  * We now trigger `sourceset` any time a `<source>` element is appended to a mediaEl with no source.
  * `load` should always fire a `sourceset`
  * `sourceset` should always be the absolute url.

src/js/player.js

@@ -2621,9 +2621,11 @@ class Player extends Component {
 
     if (!titleCaseEquals(sourceTech.tech, this.techName_)) {
       this.changingSrc_ = true;
-
       // load this technology with the chosen source
       this.loadTech_(sourceTech.tech, sourceTech.source);
+      this.tech_.ready(() => {
+        this.changingSrc_ = false;
+      });
       return false;
     }
 

src/js/tech/html5.js

@@ -35,10 +35,6 @@ class Html5 extends Tech {
   constructor(options, ready) {
     super(options, ready);
 
-    if (options.enableSourceset) {
-      this.setupSourcesetHandling_();
-    }
-
     const source = options.source;
     let crossoriginTracks = false;
 
@@ -52,6 +48,11 @@ class Html5 extends Tech {
       this.handleLateInit_(this.el_);
     }
 
+    // setup sourceset after late sourceset/init
+    if (options.enableSourceset) {
+      this.setupSourcesetHandling_();
+    }
+
     if (this.el_.hasChildNodes()) {
 
       const nodes = this.el_.childNodes;
@@ -117,6 +118,9 @@ class Html5 extends Tech {
    * Dispose of `HTML5` media element and remove all tracks.
    */
   dispose() {
+    if (this.el_.resetSourceset_) {
+      this.el_.resetSourceset_();
+    }
     Html5.disposeMediaElement(this.el_);
     this.options_ = null;