1 files changed, 76 insertions, 0 deletions
diff --git a/dom/tests/browser/browser_focus_steal_from_chrome_during_mousedown.js b/dom/tests/browser/browser_focus_steal_from_chrome_during_mousedown.js
new file mode 100644
index 0000000000..61c36f2436
--- /dev/null
+++ b/dom/tests/browser/browser_focus_steal_from_chrome_during_mousedown.js
@@ -0,0 +1,76 @@
+add_task(async function test() {
+  const kTestURI =
+    "data:text/html," +
+    '<script type="text/javascript">' +
+    "  function onMouseDown(aEvent) {" +
+    "    document.getElementById('willBeFocused').focus();" +
+    "    aEvent.preventDefault();" +
+    "  }" +
+    "</script>" +
+    '<body id="body">' +
+    '<button onmousedown="onMouseDown(event);" style="width: 100px; height: 100px;">click here</button>' +
+    '<input id="willBeFocused"></body>';
+
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, kTestURI);
+
+  let fm = Services.focus;
+
+  for (var button = 0; button < 3; button++) {
+    // Set focus to a chrome element before synthesizing a mouse down event.
+    gURLBar.focus();
+
+    is(
+      fm.focusedElement,
+      gURLBar.inputField,
+      "Failed to move focus to search bar: button=" + button
+    );
+
+    // Synthesize mouse down event on browser object over the button, such that
+    // the event propagates through both processes.
+    EventUtils.synthesizeMouse(tab.linkedBrowser, 20, 20, { button });
+
+    isnot(
+      fm.focusedElement,
+      gURLBar.inputField,
+      "Failed to move focus away from search bar: button=" + button
+    );
+
+    await SpecialPowers.spawn(
+      tab.linkedBrowser,
+      [button],
+      async function (button) {
+        let fm = Services.focus;
+
+        let attempts = 10;
+        await new Promise(resolve => {
+          function check() {
+            if (
+              attempts > 0 &&
+              content.document.activeElement.id != "willBeFocused"
+            ) {
+              attempts--;
+              content.window.setTimeout(check, 100);
+              return;
+            }
+
+            Assert.equal(
+              content.document.activeElement.id,
+              "willBeFocused",
+              "The input element isn't active element: button=" + button
+            );
+            Assert.equal(
+              fm.focusedElement,
+              content.document.activeElement,
+              "The active element isn't focused element in App level: button=" +
+                button
+            );
+            resolve();
+          }
+          check();
+        });
+      }
+    );
+  }
+
+  gBrowser.removeTab(tab);
+});