GTK3: Disable low level keyboard hook unless CSD is explicitly requested

[ouwou]

GTK installs a low level keyboard hook for its shoddy aerosnap emulation but as a side effect it makes debugging extremely painful since if the main thread blocks, the low level handler never runs causing massive latency on keystrokes: https://gitlab.gnome.org/GNOME/gtk/-/issues/2015
this patch disables it unless CSD is explicitly requested with GTK_CSD=1 since without CSD the hook serves no purpose
msys2 also applies this patch: https://github.com/msys2/MINGW-packages/blob/master/mingw-w64-gtk3/0004-Disable-low-level-keyboard-hook.patch

[danyeaw]

Hi @ouwou, thanks so much for the contribution! I recommend we add a link to the upstream issue so we can keep track of what the patch was for. Do you know if someone tried to open a MR to GTK with this change?

[ouwou]

there isnt an MR with this specifically, since iirc GTK_CSD being unset still enables CSD as a default but without the hook which technically kills some functionality. as far as i can tell there is:
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/4252 which removes the hook but looks to be targeting only gtk4
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/3331 targets gtk3 and would remove the hook but this looks dead

[danyeaw]

Thanks @ouwou