1987057 - [KDE] Press-and-hold right mouse button selection in context menus no longer works

Status: NEW

(Core :: Widget: Gtk, defect, P3)

Description

[Bernard Davis]

Attachment: A screen recording showing the issue

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:142.0) Gecko/20100101 Firefox/142.0

Steps to reproduce:

1. Start Firefox 142 on Debian 13 running KDE (tested with both Flatpak and Mozilla repository .deb versions).
2. Right-click anywhere to open a context menu and hold down right mouse button.
3. While still holding the right button, move the cursor over the menu items
4. Release the right mouse button while the cursor is over that item.

Actual results:

• No context menu item highlights while the right mouse button is held down and the pointer is moved.
• Releasing the right mouse button does not trigger any menu action.
• Unrelated parts of the UI (e.g. top-left of the tab bar, sidebar) get highlighted as though the pointer were hovering over them.

Expected results:

• The menu item under the cursor should highlight while holding the right mouse button.
• Releasing the right mouse button should trigger the highlighted menu item action, as in previous Firefox versions.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Gtk' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

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

Can you use mozregression to find broken commit?
https://fedoraproject.org/wiki/How_to_debug_Firefox_problems#Use_Mozregression_tool
Thanks.

Comment 3

[Bernard Davis]

Here is the result:

3:58.91 INFO: Narrowed integration regression window from [f3e8f920, 62f1dc92] (3 builds) to [aeb150a0, 62f1dc92] (2 builds) (~1 steps left)
3:58.91 INFO: No more integration revisions, bisection finished.
3:58.91 INFO: Last good revision: aeb150a06b3eeeab56a698b26d9a487c891fd7a9
3:58.91 INFO: First bad revision: 62f1dc9218204d41aabac5efc3cb0a2f193dd2d2
3:58.91 INFO: Pushlog:
https://hg.mozilla.org/releases/mozilla-release/pushloghtml?fromchange=aeb150a06b3eeeab56a698b26d9a487c891fd7a9&tochange=62f1dc9218204d41aabac5efc3cb0a2f193dd2d2

Comment 4

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

That's quite large list but I suspect Bug 1976600 / Bug 1975969 is related.
Can you please run on terminal with MOZ_LOG="Widget:5 WidgetPopup:5" env variables, reproduce it and attach the log here?
Thanks.

Comment 5

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

Also please attach your about:support page.
Thanks.

Comment 6

[Bernard Davis]

Attachment: about:support output

Comment 7

[Bernard Davis]

Attachment: log.moz_log

Comment 8

[Bernard Davis]

Hi, I have attached the log and about:support output (using copy text to clipboard option).

Thanks

Comment 9

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

Will look at it, Thanks.

Comment 10

[Kestrel]

Reproducible on Kubuntu 25.04 live USB when right-clicking and holding in the top-left area of window. Does not happen when clicking near the bottom/right window edges.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=ed7e3db508c63f50de14a9a80555f981f5a2b49a&tochange=c4f44b8fb561a31435a47407ae135b59e9500962

Regressed by Bug 1975969.

Comment 11

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

Set release status flags based on info from the regressing bug 1975969

Comment 12

[deadmeu]

(In reply to Kestrel from comment #10)

Reproducible on Kubuntu 25.04 live USB when right-clicking and holding in the top-left area of window. Does not happen when clicking near the bottom/right window edges.

Wow, you're right. It only seems to happen when the context menu grows downwards and starts from the right of the cursor. When the cursor is either too far low enough on the page (context menu will grow upwards) or too far to the right (context menu starts to the left of the cursor) the issue does not present itself.

Comment 14

[Tem PQD [:tempqd]]

Same as Bug 1984812?

Comment 15

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

Yes, perhaps. But let's leave it separated for now.

Comment 16

[Kestrel]

Bug 1984812's description, conditions, screencaps, affected versions and regression window all match.

Comment 17

[Łukasz]

I have the same bug on GNOME Shell 49 Wayland with Firefox 144.

Comment 18

[LewisMCYT]

This same issue occurs for me on my installation of Arch Linux with KDE Plasma. I have tested in a virtual machine using the live ISO of KDE neon and it also occurs there. However, the bug does not occur if the window renderer (as shown in about:support) is xwayland instead of wayland. (In my Arch Linux installation, I can run Firefox with xwayland by running MOZ_ENABLE_WAYLAND=0 firefox in the terminal.)