Bug 1615732 - Don't show download panel on Mac when ctrl key is pressed; r=Gijs

On Mac, ctrl-click will send a context menu event from the widget, so we don't
want to bring up the panel when ctrl key is pressed.

Differential Revision: https://phabricator.services.mozilla.com/D66414

--HG--
extra : moz-landing-system : lando

browser/components/downloads/content/indicator.js

@@ -568,7 +568,11 @@ const DownloadsIndicatorView = {
 
   onCommand(aEvent) {
     if (
-      (aEvent.type == "mousedown" && aEvent.button != 0) ||
+      // On Mac, ctrl-click will send a context menu event from the widget, so
+      // we don't want to bring up the panel when ctrl key is pressed.
+      (aEvent.type == "mousedown" &&
+        (aEvent.button != 0 ||
+          (AppConstants.platform == "macosx" && aEvent.ctrlKey))) ||
       (aEvent.type == "keypress" && aEvent.key != " " && aEvent.key != "Enter")
     ) {
       return;

browser/components/downloads/test/browser/browser.ini

@@ -15,6 +15,7 @@ skip-if = (os == 'win' && os_version == '10.0' && ccov) # Bug 1306510
 [browser_library_clearall.js]
 [browser_downloads_panel_block.js]
 skip-if = true # Bug 1352792
+[browser_downloads_panel_ctrl_click.js]
 [browser_downloads_panel_height.js]
 [browser_downloads_autohide.js]
 [browser_go_to_download_page.js]

browser/components/downloads/test/browser/browser_downloads_panel_ctrl_click.js

@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_downloads_panel() {
+  // On macOS, ctrl-click shouldn't open the panel because this normally opens
+  // the context menu. This happens via the `contextmenu` event which is created
+  // by widget code, so our simulated clicks do not do so, so we can't test
+  // anything on macOS.
+  if (AppConstants.platform == "macosx") {
+    ok(true, "The test is ignored on Mac");
+    return;
+  }
+
+  await SpecialPowers.pushPrefEnv({
+    set: [["browser.download.autohideButton", false]],
+  });
+  await promiseButtonShown("downloads-button");
+
+  const button = document.getElementById("downloads-button");
+  let shownPromise = promisePanelOpened();
+  // Should still open the panel when Ctrl key is pressed.
+  EventUtils.synthesizeMouseAtCenter(button, { ctrlKey: true });
+  await shownPromise;
+  is(DownloadsPanel.panel.state, "open", "Check that panel state is 'open'");
+
+  // Close download panel
+  DownloadsPanel.hidePanel();
+  is(
+    DownloadsPanel.panel.state,
+    "closed",
+    "Check that panel state is 'closed'"
+  );
+});