Bug 2003810 - [devtools] Nullify WindowGlobalTarget actor when the underlying WindowGlobal navigated to another origin and process. r=devtools-reviewers,jdescottes a=dmeehan

This prevents having to special case the "isRemoteProxy" edgecase in all actors.

Differential Revision: https://phabricator.services.mozilla.com/D277446

Author: ochameau

devtools/client/inspector/test/browser.toml

@@ -154,6 +154,8 @@ skip-if = [
 
 ["browser_inspector_picker-no-page-events.js"]
 
+["browser_inspector_picker-page-reload.js"]
+
 ["browser_inspector_picker-reset-reference.js"]
 
 ["browser_inspector_picker-shift-key.js"]

devtools/client/inspector/test/browser_inspector_picker-page-reload.js

@@ -0,0 +1,94 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Test that the node picker works while reloading a page with
+// an iframe going through an intermediate about:blank document
+
+const FRAME_URL = "https://example.com/document-builder.sjs?html=iframe";
+const TEST_URL =
+  `https://example.org/document-builder.sjs?html=` +
+  encodeURI(
+    `<h1>Pick target</h1><h2>Other element</h2><iframe></iframe><script>window.onload=()=>{document.querySelector("iframe").src = "${FRAME_URL}";}</script>`
+  );
+
+async function waitForIframeLoad() {
+  const iframeBC = await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [],
+    function () {
+      return content.document.querySelector("iframe").browsingContext;
+    }
+  );
+  await SpecialPowers.spawn(iframeBC, [FRAME_URL], async function (url) {
+    if (
+      content.document.readyState == "complete" &&
+      content.location.href == url
+    ) {
+      return null;
+    }
+    return new Promise(resolve => {
+      content.addEventListener("load", resolve, { once: true });
+    });
+  });
+}
+
+add_task(async () => {
+  let { inspector, toolbox, highlighterTestFront } =
+    await openInspectorForURL(TEST_URL);
+  await waitForIframeLoad();
+
+  info(
+    "Start the picker and hover an element to populate the picker hovered node reference"
+  );
+  await startPicker(toolbox);
+  await hoverElement(inspector, "iframe");
+
+  const HIGHLIGHTER_TYPE = inspector.highlighters.TYPES.BOXMODEL;
+  const { getActiveHighlighter } = getHighlighterTestHelpers(inspector);
+
+  ok(getActiveHighlighter(HIGHLIGHTER_TYPE), "Boxmodel highlighter is shown.");
+  ok(
+    await highlighterTestFront.assertHighlightedNode("iframe"),
+    "The highlighter is shown on the expected node"
+  );
+
+  // Do not wait for full reload as the faulty target for transient about:blank
+  // document may already be destroyed and not cause troubles anymore
+  const onReloaded = reloadSelectedTab();
+
+  // Bug 2003810: hovering during the navigation may throw error in the content process,
+  // but this exception wouldn't make the test fail anyway.
+  hoverElement(inspector, "h1");
+
+  await onReloaded;
+
+  // As the previous hover may not complete, we have to do another one once the page is loaded
+  await hoverElement(inspector, "h1");
+  ok(getActiveHighlighter(HIGHLIGHTER_TYPE), "Boxmodel highlighter is shown.");
+
+  highlighterTestFront = await getHighlighterTestFront(toolbox);
+  ok(
+    await highlighterTestFront.assertHighlightedNode("h1"),
+    "The highlighter is shown on the expected node"
+  );
+
+  await stopPickerWithEscapeKey(toolbox);
+
+  // Bug 2003810 highlighted that the toolbox couldn't be re-opened
+  // as the broken, not correctly unregistered/disabled node-picker was keeping
+  // its suppressedEventListener active and possibly disable all further key presses.
+  // But there is no way to reproduce the exact same keypress event.
+  // BrowserTestUtils.synthesizeKey/EventUtils.synthesizeNativeKey both seem to send the event only to the content.
+  // And EventUtils.synthesizeKey doesn't, but avoids reproducing the regression.
+  const onToolboxDestroyed = toolbox.once("destroyed");
+  info("Try to close the toolbox via a key shortcut");
+  if (Services.appinfo.OS == "Darwin") {
+    EventUtils.synthesizeKey("i", { accelKey: true, altKey: true });
+  } else {
+    EventUtils.synthesizeKey("i", { accelKey: true, shiftKey: true });
+  }
+  await onToolboxDestroyed;
+});

devtools/server/actors/inspector/node-picker.js

@@ -389,6 +389,7 @@ class NodePicker {
    * @param callback The function to call with suppressed events, or null.
    */
   _setSuppressedEventListener(callback) {
+    // The related document may already have been destroyed, or moved to another origin/process.
     if (!this._targetActor?.window?.document) {
       return;
     }

devtools/server/actors/targets/window-global.js

@@ -414,7 +414,7 @@ class WindowGlobalTargetActor extends BaseTargetActor {
       });
       Object.defineProperty(this, "window", {
         value: this.window,
-        configurable: false,
+        configurable: true,
         writable: false,
       });
       Object.defineProperty(this, "chromeEventHandler", {
@@ -806,6 +806,17 @@ class WindowGlobalTargetActor extends BaseTargetActor {
     }
     this.destroying = true;
 
+    // In case the window already navigated to another origin,
+    // which is possibly in another process, nullify window
+    // as most, if not all attributes would throw.
+    if (Cu.isRemoteProxy(this.window)) {
+      Object.defineProperty(this, "window", {
+        value: null,
+        configurable: true,
+        writable: false,
+      });
+    }
+
     // Force flushing pending resources if the actor isn't already destroyed.
     // This helps notify the client about pending resources on navigation.
     if (!this.isDestroyed()) {