Fail gracefully instead of crashing if grab fails with the error "Could not grab modal"

[icyflame]

I have been using PaperWM on a daily basis for the past few months and it is great. One of the problems that I kept running into repeatedly was #991. This issue was reported on Gnome 47. I ran into this problem on Gnome 42.9.

I attempted a naive fix which simply tries to clean-up all the state instead of crashing. This works well; I have been using a version of this fix, applied on top of the gnome-44 branch, for the past month and I have not suffered any Could not grab modal crashes. I have backported this change to the gnome-44 branch as well: #1032.

It would be great if I could get some guidance about whether this fix looks logical, and whether there might be a way to reproduce this code path somehow. We need to somehow get into preview_navigate (which happens when one uses a keyboard shortcut to switch windows, I believe?) but get there in a state where the keyboard is already grabbed by something else, thus causing PaperWM to fail to grab the keyboard.

Meanwhile, I will continue to use PaperWM daily on two machines (albeit with old Gnome versions: 3.38 and 42.9) I will attempt to get PaperWM up and running on a more recent version and check to see if I run into this crash on the default branch; if I do, then, I will also see whether this fix solves the crash.

I would really like to fix this issue within PaperWM (upstream) because I have not run into any other bug at all and this is a great project!

[jtaala]

See comments on #1032.

Thanks @icyflame - I haven't seen this issue on later Gnome versions (e.g. current 47 etc.). Although, that may be due to how I use PaperWM etc.

Let me know if succeed in seeing this issue in latest gnome and PaperWM. If so, I'm happy to run this branch for a few days just to make sure it doesn't introduce any other issues (and if not, can merge).

Cheers.