1806996 - [Linux] Dragging links from Firefox into other apps just stops working - XdndFinished is missing

Status: UNCONFIRMED

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

Description

[tomaspollak]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:108.0) Gecko/20100101 Firefox/108.0

Steps to reproduce:

As the title says, when I drag a link from Firefox into other apps it works seems to work the first time. After dropping that first link, dragging just doesn't work. It seems to happen with apps that probably don't respond properly to X11 DND messages.

For instance I am able to drag several link into Sublime Text, but if I try dragging a link to my terminal emulator (ie. for fetching it via wget) then I get the erratic behaviour.

Actual results:

Dragging stopped working after the first link was dropped.

Expected results:

I should be able to drag links to infinity and beyond! Chrome doesn't suffer from this problem by the way.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::DOM: Copy & Paste and Drag & Drop' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[tomaspollak]

Attachment: Quick demo showing the issue

Comment 3

[tomaspollak]

Attachment: Quick demo showing the issue

Comment 4

[Darkspirit]

Thanks for the report! Which desktop environment, terminal (package) and Linux distribution are you using?

Please check if this is a regression:
$ pip3 install --upgrade mozregression
$ ~/.local/bin/mozregression --good 100 --bad 2022-12-22 -a https://example.org

Comment 5

[tomaspollak]

Xubuntu, XFCE and Exoterm (a personal fork of rxvt-unicode).

Comment 6

[tomaspollak]

I get the same behaviour using the version launched by mozregression

Comment 7

[tomaspollak]

Ok just confirmed this happens when dropping stuff on windows that do not send the XdndFinished event back to the FIrefox window (source/originator of the DND event). Chrome somehow manages to handle this situation correctly, however Firefox keeps waiting for the XdndFinished event (which never arrives) and thus DND stops working altogether.

I found out about this because I'm building an app using the the Sokol libs, and apparently Sokol isn't sending the XdndFinished event. My fork of urxvt (which I added DND support to) also didn't because I based my implementation on what Sokol did. :)

Comment 8

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

Can you try a different Gtk3 application like gtk3-widget-factory? I wonder if that's a bug in Gtk3 library or is that Firefox specific.
Thanks.

Comment 9

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

XdndDirect is finished here:
https://searchfox.org/mozilla-central/rev/0907529ff72c456ddb47839f5f7ba16291f28dce/widget/gtk/nsDragService.cpp#1442

so I wonder if we miss such call here.