1432385 - [LXQt + xfwm4] Fcitx candidate window is black (nightly 2018-01-17-10-01-29 regression)

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect, P2)

Description

[Chih-Hsuan Yen [:yan12125] (UTC+8)]

Attachment: 2018-01-23 13-44-11 的螢幕擷圖.png

With recent Nightly, fcitx-chewing candidate window becomes black.

Steps to reproduce:
1. Install both fcitx and fcitx-chewing
2. Pick a text box
3. Hit 5j/
   (Corresponds to ㄓㄨㄥ in Chinese)

Result:
The candidate window has a black background, making it hard to read (see screenshot below)

I've tested multiple Nightly versions, and looks like it's a regression:

2018-01-13-10-02-55 good
2018-01-15-10-00-56 good
2018-01-16-10-01-14 good
2018-01-16-22-01-10 good
2018-01-17-10-01-29 bad
2018-01-17-22-03-27 bad

Comment 1

[Chih-Hsuan Yen [:yan12125] (UTC+8)]

Attachment: 2018-01-23 12-46-15 的螢幕擷圖.png

Screenshot for versions <= 2018-01-16-22-01-10: the candidate window has normal background color

Comment 2

[Chih-Hsuan Yen [:yan12125] (UTC+8)]

Hello Martin Stránský,

After testing with many changesets on mozilla-central, I find my issue related to one of your previous changes. Could you have a look?

bad     d88cb52f392d 2018-01-15 09:08 -0800 	Ralph Giles - Bug 1430188: av1: Mark AOM_QM matricies const. r=kinetik.
bad     8dee5d879ef1 2018-01-12 08:41 +0100 	Martin Stransky - Bug 1420818 - For rendering to titlebar make CSD window decorations mode default, enable WM decorations on Elementary OS, r=jhorak
good    fe6f236e1fb5 2018-01-16 14:28 -0500 	Kartikaya Gupta - Bug 1430797 - Allow webrender on eWindowType_child, so that it is used on OS X. r=nical
good    195e88aab631 2018-01-09 16:48 +0100 	Julien Wajsberg - Bug 1429094 - Define the environment variable HGRCPATH to ignore any .hgrc that may exist r=gps

I've done more tests on 8dee5d879ef1:

* MOZ_GTK_TITLEBAR_DECORATION=none ./mach run => good (blue background + white characters like my second screenshot)
* MOZ_GTK_TITLEBAR_DECORATION=client ./mach run => broken (black background + black characters like my first screenshot)
* MOZ_GTK_TITLEBAR_DECORATION=system ./mach run => good

Looking at 8dee5d879ef1, I think it's not so correct. The default value of sCSDSupportLevel shouldn't be touched. In other words, it should remain CSD_SUPPORT_NONE.

My environment: LXQt ($XDG_CURRENT_DESKTOP=LXQt) + xfwm4

Comment 3

[Martin Stránský [:stransky] (ni? me)]

I'll look at it. My guess is that you don't have compositing WM.

Comment 4

[Martin Stránský [:stransky] (ni? me)]

We should fix that also for Firefox 59 as it's affected by this.

Comment 5

[Chih-Hsuan Yen [:yan12125] (UTC+8)]

> My guess is that you don't have compositing WM.

Thanks for the hint. Indeed compositing was not enabled. After enabling it (xfwm4-tweaks-settings -> Compositor -> Enable display compositing) and re-login, nothing has changed. fcitx-chewing candidate window is still broken if MOZ_GTK_TITLEBAR_DECORATION is `client` or unspecified.

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Attachment: Bug 1432385 - Use window manager borders on LXQt,

Review commit: https://reviewboard.mozilla.org/r/215618/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/215618/

Comment 7

[Jan Horak [:jhorak]]

Comment on attachment 8945441 [details]
Bug 1432385 - Use window manager borders on LXQt,

https://reviewboard.mozilla.org/r/215618/#review221950

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c6b717a7f871
Use window manager borders on LXQt, r=jhorak

Comment 9

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/c6b717a7f871

Comment 10

[Julien Cristau [:jcristau]]

Per comment 4, please request uplift to beta when you get a chance.

Comment 11

[Martin Stránský [:stransky] (ni? me)]

Comment on attachment 8945441 [details]
Bug 1432385 - Use window manager borders on LXQt,

Approval Request Comment
[Feature/Bug causing the regression]: none
[User impact if declined]: LXQt won't have working CSD/titlebar rendering.
[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]: no
[Is the change risky?]: no
[Why is the change risky/not risky?]: The fixed feature is off by default.
[String changes made/needed]: none

Comment 12

[Ritu Kothari (:ritu) (Inactive, please n-i to RyanVM, jcristau, or pascal)]

Comment on attachment 8945441 [details]
Bug 1432385 - Use window manager borders on LXQt,

Recent regression in 59, seems safe, Beta59+

Comment 13

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/releases/mozilla-beta/rev/0128f159f3a3