Steps to reproduce:

1. Start Firefox on a Windows PC.
2. Right-click on the toolbar and check "Menu Bar" to show it always.
3. Hit Ctrl-Shift-K to open the Web Console.
4. Input window.open('about:blank','_blank','toolbar') and hit Enter key.
5. The popup is blocked by Firefox's popup blocker, thus click the "allow to open
   the requested window.

Actual result:

A browser window is opened without window controls.
(See the attached screenshot: missing-window-controls.png)

Expected result:

A browser window is opened with window controls.

Envrionment:

• Confirmed versions of Firefox
  • Firefox 65.0b12 (build ID: 20190117232427)
  • Nightly 66.0a1 (build ID: 20190121175139)
• Confirmed platform
  • Windows 7
  • Windows 10

Additional information:

• If you uncheck the "Menu Bar" to show it on demand, the opened window has window controls. This problem appears only with always-shown menu bar.
• On Firefox 64 or older versions, window controls become unclickable if you use the Classic theme of Windows 7, because the #tabbrowser-tab with z-index:2 [1] covers #titlebar-buttonbox with z-index:1 [2].

[1]https://dxr.mozilla.org/mozilla-esr60/source/browser/themes/windows/browser.css#206
[2]https://dxr.mozilla.org/mozilla-esr60/source/browser/themes/windows/browser.css#305

I've filed the bug 1521692 for a similar probelm on currently released Firefox.

Initial version patch, without automated test.

I have a question: is there the suitable location to place automated test? I've found possible related tests under:

• https://hg.mozilla.org/mozilla-central/file/tip/browser/base/content/test/
• https://hg.mozilla.org/mozilla-central/file/tip/toolkit/components/windowwatcher/test/

(In reply to YUKI "Piro" Hiroshi from comment #2)

Created attachment 9038164 [details] [diff] [review]
Patch (WIP)

Initial version patch, without automated test.

I have a question: is there the suitable location to place automated test?

https://searchfox.org/mozilla-central/source/browser/base/content/test/popups/browser_popupUI.js

(In reply to Dão Gottwald [::dao] from comment #3)

(In reply to YUKI "Piro" Hiroshi from comment #2)

I have a question: is there the suitable location to place automated test?

https://searchfox.org/mozilla-central/source/browser/base/content/test/popups/browser_popupUI.js

Thanks!

Now I'm trying to write tests. Here is a list of conditions thought as need to be tested:

• browser.tabs.drawInTitlebar (on/off)
• window.open() flags
  • (no feature)
  • toolbar
  • menubar
  • toolbar,menubar
• View => Toolbars => Menu Bar (on/off)

I think https://searchfox.org/mozilla-central/source/toolkit/components/windowwatcher/test/browser_new_content_window_chromeflags.js looks an example for testing with combinations of conditions.

https://hg.mozilla.org/mozilla-central/rev/7d8248d94084