1751339 - nightly breaks input method window position if title bar is disabled

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect)

Description

[Weng Xuetian]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

1. Disable title bar
2. type with input method

System is X11/KDE.

Actual results:

input method window is shown in the wrong position

Expected results:

input method window is shown in the correct position

2022-01-02-21-36-25-mozilla-central is the last nightly without this problem.
2022-01-03-09-29-29-mozilla-central is the first nightly with this problem.

Comment 1

[Weng Xuetian]

Sorry I was confused by the nightly auto update, the first version that introduce this problem is
https://ftp.mozilla.org/pub/firefox/nightly/2022/01/2022-01-17-21-49-41-mozilla-central/firefox-98.0a1.en-US.linux-x86_64.tar.bz2

Comment 2

[Alice0775 White]

Given the above comments, the regression window is:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=256b8ee1c2cf7a1f08b903738344a5aacf97bde3&tochange=352dec7d8c1349d30c72fdefea648d47ad7cab08

Suspect: Bug 1747919

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1747919

Comment 4

[Weng Xuetian]

With my Gtk knowledge, I think the culprit is caused by this commit:
https://hg.mozilla.org/mozilla-central/rev/1508310c3f8c6df8b3e36a53ccb0b1b3a72ea59c

Right now the observation is that the GdkWindow passed to gtk_im_context_set_client_window is now a destroyed window (gdk_window_is_destroyed() == true).

It might need a refresh to update im context's client window to the new gdk window.

Comment 5

[Robert Mader [:rmader]]

(In reply to Weng Xuetian from comment #4)

With my Gtk knowledge, I think the culprit is caused by this commit:
https://hg.mozilla.org/mozilla-central/rev/1508310c3f8c6df8b3e36a53ccb0b1b3a72ea59c

Thanks, can confirm that's the issue. Unfortunately I currently have very limited time to dive deeper into this, thus I'll propose to just revert the commit for now.

Comment 6

[Robert Mader [:rmader]]

Attachment: Bug 1751339 - Revert "Replace gtk_widget_reparent", r=emilio

Switching to gtk_container_[add|remove] not only looked less
elegant but also broke input method window positions. Revert
it for now, until someone has time to dive deeper into the issue.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a076f89f293b
Revert "Replace gtk_widget_reparent", r=emilio

Comment 8

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/a076f89f293b