1316387 - Firefox menu items are too tall when Windows display scaling is > 100% (after recent Insider Preview update)

Status: RESOLVED INCOMPLETE

(Core :: Widget: Win32, defect)

Description

[Chris Peterson [:cpeterson]]

Attachment: Screenshot_of_tall_menus.png

I have a HiDPI screen with the display scaling set to 250%, the default value on my laptop. See the attached screenshot. This setting can be changed in Windows Settings > Display > "Change the size of text, apps, and other items". If I change the display scale to 100% (no scaling), then Firefox's menu items are the expected height.

I'm using Microsoft's Windows 10 Insider Preview "Slow" channel, if that matters. I think this menu problem first started happening after the recent Insider Preview update. This is not a Firefox regression because the problem affects all Firefox channels 49-52.

Comment 1

[Alice0775 White]

The problem is since 47

Comment 2

[Alice0775 White]

Regression window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=fbb40278805ff5a8aac8b1a1dbd8b0a180f82296&tochange=05cf733d5b26369caeca4550a0d33e9fd099b622

Regressed by: 05cf733d5b26	Jonathan Kew — Bug 1254020 - Always compute theme scaling factor when per-monitor dpi aware, even if only a single display is currently present. r=emk

Comment 3

[Masatoshi Kimura [:emk]]

Did you sign out & sign in after changing the dpi?

Comment 4

[Chris Peterson [:cpeterson]]

(In reply to Masatoshi Kimura [:emk] from comment #3)
> Did you sign out & sign in after changing the dpi?

For some reason I am no longer able to reproduce the problem today, but when I could, signing out or rebooting didn't seem to make a difference.

@ Alice, with which version of Windows did you reproduce the problem? I am currently running Windows 10 Home Insider Preview build 14931.rs_prerelease.160916-1700 (according to the version info on my desktop).

Comment 5

[Alice0775 White]

Easy to reproduce, set user_pref("layout.css.devPixelsPerPx", "2.5"); and restart.

Reproduce on Windows10 version 1607 build 14393.447 and version 1607 build 14965.1001.
Reproduce on Windows8.1.
Not reproduce on Windows7.

Comment 6

[Masatoshi Kimura [:emk]]

The non-default "layout.css.devPixelsPerPx" issue would be a different problem and should be tracked by another bug.

Comment 7

[Alice0775 White]

okay i have filed Bug 1316717

Comment 8

[Maire Reavy [:mreavy]]

If anyone can repro this, we can reopen.

Comment 9

[Alice0775 White]

Attachment: screenshot

Menubar, Bookmarks toolbar, Context menu, Liblary's Menubar are affected at least.