User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:58.0) Gecko/20100101 Firefox/58.0 Build ID: 20170922220129 Steps to reproduce: Open a regular Firefox Nightly session with the browser configured to display the title bar. Actual results: The title bar is visible but there is no text on it. Expected results: The title bar text is visible and displays the title for the current tab.

Thanks for reporting and it was immediately clear what's going on here. This mistake was left over from the previously, only intermittently working patch in bug 1398582 (attachment 8908650 [details] [diff] [review]). Switching between showing and hiding the native title bar works because setDrawsContentsIntoWindowFrame: is called every time. However, if a profile is set to display the native title bar and Firefox is restarted, we don't get an initial call to setDrawsContentsIntoWindowFrame:. Therefore, we should default to showing titles and titlebars and hide them as soon as we get a setDrawsContentsIntoWindowFrame: call.

https://hg.mozilla.org/integration/mozilla-inbound/rev/f55d4f566a2d93202e55983fa6ccffa469628f5b Bug 1402577: Display titles in titlebar on macOS when the native titlebar is in use. r=mstange

let's uplift this to beta once verified in nightly.

Comment on attachment 8911524 [details] [diff] [review] Patch Approval Request Comment [Feature/Bug causing the regression]: Bug 1398582 [User impact if declined]: Window titles don't display when users have native title bars enabled on macOS. [Is this code covered by automated tests?]: No [Has the fix been verified in Nightly?]: Yes [Needs manual test from QE? If yes, steps to reproduce]: No [List of other uplifts needed for the feature/fix]: None [Is the change risky?]: No [Why is the change risky/not risky?]: Isolated, well understood change. [String changes made/needed]:

(In reply to Stephen A Pohl [:spohl] from comment #6) > [String changes made/needed]: This should have been "none".

Comment on attachment 8911524 [details] [diff] [review] Patch Fix a visual glitch. Taking it, should be in 57b4