Auto merge of #20837 - gterzian:tests_for_has_event_listener, r=cbrewster

Fix for document salvageable state

I noticed a bug where if the document was un-salavageable due to the presence of `beforeunload` listeners, this could be overwritten if there were no listeners for `unload`. This could also have happened if an iframe of the document had no listeners while the parent did.

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- [ ] These changes fix #__ (github issue number if applicable).

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components/script/dom/document.rs

@@ -1665,7 +1665,9 @@ impl Document {
         );
         // TODO: Step 6, decrease the event loop's termination nesting level by 1.
         // Step 7
-        self.salvageable.set(!has_listeners);
+        if has_listeners {
+            self.salvageable.set(false);
+        }
         let mut can_unload = true;
         // TODO: Step 8, also check sandboxing modals flag.
         let default_prevented = event.DefaultPrevented();
@@ -1681,9 +1683,11 @@ impl Document {
             for iframe in self.iter_iframes() {
                 // TODO: handle the case of cross origin iframes.
                 let document = document_from_node(&*iframe);
-                if !document.prompt_to_unload(true) {
-                    self.salvageable.set(document.salvageable());
-                    can_unload = false;
+                can_unload = document.prompt_to_unload(true);
+                if !document.salvageable() {
+                   self.salvageable.set(false);
+                }
+                if !can_unload {
                     break;
                 }
             }
@@ -1734,7 +1738,9 @@ impl Document {
             );
             self.fired_unload.set(true);
             // Step 9
-            self.salvageable.set(!has_listeners);
+            if has_listeners {
+                self.salvageable.set(false);
+            }
         }
         // TODO: Step 8, decrease the event loop's termination nesting level by 1.
 

tests/wpt/metadata/MANIFEST.json

@@ -275100,6 +275100,16 @@
      {}
     ]
    ],
+   "html/browsers/browsing-the-web/unloading-documents/prompt/004-1.html": [
+    [
+     {}
+    ]
+   ],
+   "html/browsers/browsing-the-web/unloading-documents/prompt/004-2.html": [
+    [
+     {}
+    ]
+   ],
    "html/browsers/browsing-the-web/unloading-documents/prompt/manual-001.html": [
     [
      {}
@@ -331319,6 +331329,12 @@
      {}
     ]
    ],
+   "html/browsers/browsing-the-web/unloading-documents/prompt/004.html": [
+    [
+     "/html/browsers/browsing-the-web/unloading-documents/prompt/004.html",
+     {}
+    ]
+   ],
    "html/browsers/browsing-the-web/unloading-documents/unload/001.html": [
     [
      "/html/browsers/browsing-the-web/unloading-documents/unload/001.html",
@@ -561520,6 +561536,18 @@
    "c37ad1ea3a1c8e389f6066c95c7b2745648e9e7e",
    "testharness"
   ],
+  "html/browsers/browsing-the-web/unloading-documents/prompt/004-1.html": [
+   "3530a94754361d436b6c20496bea07eb0bec4893",
+   "support"
+  ],
+  "html/browsers/browsing-the-web/unloading-documents/prompt/004-2.html": [
+   "01dc2c7f9c673781291a5afbdb40ca0f0919e797",
+   "support"
+  ],
+  "html/browsers/browsing-the-web/unloading-documents/prompt/004.html": [
+   "4c8485a929926005115dd0f8e2d2a2d8e1673c6f",
+   "testharness"
+  ],
   "html/browsers/browsing-the-web/unloading-documents/prompt/manual-001.html": [
    "895580cf70904918397da755527c5dda3f227b8a",
    "support"

tests/wpt/web-platform-tests/html/browsers/browsing-the-web/unloading-documents/prompt/004-1.html

@@ -0,0 +1,28 @@
+<!doctype html>
+004-1
+<script>
+var handleBeforeUnload = function() {
+  parent.beforeunload_fired = true;
+  removeListener();
+  setTimeout(function() {
+    parent.timeout_fired = true;
+  }, 1000);
+}
+
+var removeListener = function() {
+  assert_true(window.removeEventListener('beforeunload', handleBeforeUnload, false));
+}
+
+window.addEventListener('beforeunload', handleBeforeUnload, false);
+
+onload = function() {
+  if (!parent.loaded) {
+    parent.loaded = true;
+    location="004-2.html?" + Math.random();
+  }
+}
+</script>
+// child frame with no onbeforeunload listener. Should leave the parent as unsalvageable.
+// Adding the iframe prevents potential implementation bugs where the the recursive steps of #prompt-to-unload-a-document
+// would overwrite the salvageable state of the parent.
+<iframe></iframe>

tests/wpt/web-platform-tests/html/browsers/browsing-the-web/unloading-documents/prompt/004-2.html

@@ -0,0 +1,5 @@
+<!doctype html>
+004-2
+<script>
+onload = function() {setTimeout(parent.t.step_func(function() {parent.start_test(); history.go(-1)}), 100)}
+</script>

tests/wpt/web-platform-tests/html/browsers/browsing-the-web/unloading-documents/prompt/004.html

@@ -0,0 +1,29 @@
+<!doctype html>
+<title>salvagable state of document after setting beforeunload listener</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var t = async_test();
+
+var loaded = false;
+var beforeunload_fired = false;
+var timeout_fired = false;
+
+function start_test() {
+  step_timeout(
+    t.step_func(function() {
+      assert_true(beforeunload_fired);
+      assert_false(timeout_fired);
+      t.done()
+    }), 1000);
+}
+
+onload = function() {
+  var iframe = document.getElementsByTagName("iframe")[0]
+  onload = null;
+  iframe.src="004-1.html?" + Math.random();
+};
+
+</script>
+<iframe></iframe>