gnome shell uses the wrong window icon

[Antoine Martin]

We try very hard to ensure that despite the fact that all the windows we forward will be owned by the same xpra process, we set a different group-leader (see "get_group_leader"), we forward the wm-class and the window icon.
Unfortunately, gnome-shell will use the first icon we set for all the windows.. Can be tested easily with this standalone app: test_window_icons.py

There could be other window managers that do the wrong thing here, but gnome-shell is the only one I am aware of.
Tested: Ubuntu's Unity, MS Windows, KDE, etc.. no problem with any of those. (macos, as usual, does its own thing: only one dock entry.. which we could change when a different application gets focus?)

This may require submitting a patch upstream..

[Antoine Martin]

I believe this is no longer the case since #1144, will re-check.

[Antoine Martin]

Still a problem. All the window properties are set correctly, but gnome-shell uses something else... sigh.

[Antoine Martin]

Fixed in r17250: we create a fake process for each server-side pid, this ensures that gnome-shell does the right thing.
We can later use it for handling client-side signals sent to the process owning a window: #1671.

Found some references along the way:

• ​shell-window-tracker.c is where the window to application logic lives and there have been quite a few issues with it: ​commits, ​Bug 736527 - app-switcher not working when certain windows (jdownloader2 notifications) are shown
• ​Application Specification: tried to set _GTK_APPLICATION_ID to a unique string, but that didn't have any effect and would interfere with menu forwarding

[Antoine Martin]

Missing bits added in r17253 (caused #1672).

[Antoine Martin]

r17272: missing man page

[Antoine Martin]

r17362: minor cleanup in and avoid trying on macos

[Antoine Martin]

missed Debian packaging: r17598