1 files changed, 52 insertions, 0 deletions
diff --git a/browser/base/content/test/zoom/browser_subframe_textzoom.js b/browser/base/content/test/zoom/browser_subframe_textzoom.js
new file mode 100644
index 0000000000..e5d40cf585
--- /dev/null
+++ b/browser/base/content/test/zoom/browser_subframe_textzoom.js
@@ -0,0 +1,52 @@
+/* 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/. */
+
+/*
+ * Test the fix for bug 441778 to ensure site-specific page zoom doesn't get
+ * modified by sub-document loads of content from a different domain.
+ */
+
+function test() {
+  waitForExplicitFinish();
+
+  const TEST_PAGE_URL = 'data:text/html,<body><iframe src=""></iframe></body>';
+  // eslint-disable-next-line @microsoft/sdl/no-insecure-url
+  const TEST_IFRAME_URL = "http://test2.example.org/";
+
+  (async function () {
+    // Prepare the test tab
+    let tab = BrowserTestUtils.addTab(gBrowser);
+    await FullZoomHelper.selectTabAndWaitForLocationChange(tab);
+
+    let testBrowser = tab.linkedBrowser;
+
+    await FullZoomHelper.load(tab, TEST_PAGE_URL);
+
+    // Change the zoom level and then save it so we can compare it to the level
+    // after loading the sub-document.
+    FullZoom.enlarge();
+    var zoomLevel = ZoomManager.zoom;
+
+    // Start the sub-document load.
+    await new Promise(resolve => {
+      executeSoon(function () {
+        BrowserTestUtils.browserLoaded(testBrowser, true).then(url => {
+          is(url, TEST_IFRAME_URL, "got the load event for the iframe");
+          is(
+            ZoomManager.zoom,
+            zoomLevel,
+            "zoom is retained after sub-document load"
+          );
+
+          FullZoomHelper.removeTabAndWaitForLocationChange().then(() =>
+            resolve()
+          );
+        });
+        SpecialPowers.spawn(testBrowser, [TEST_IFRAME_URL], url => {
+          content.document.querySelector("iframe").src = url;
+        });
+      });
+    });
+  })().then(finish, FullZoomHelper.failAndContinue(finish));
+}