Prevent using a wlr_layer_surface after destroying it

[minego]

If the createlayersurface callback is hit when selmon is NULL then wlr_layer_surface is destroyed by calling wlr_layer_surface_v1_destroy(). This change simply adds a return at that point, to prevent a crash caused by dereferencing the destroyed variable.

The crash in question can be reproduced easily by unplugging or turning off all monitors while running swaync, waiting a few seconds and then plugging them back in. It is likely possible to cause this with things other than swaync, but that was the application that triggered it for me.

[sevz17]

Thanks!

[minego]

Thank you!

…

On Thu, May 25, 2023, at 9:22 PM, Leonardo Hernández wrote: Thanks! — Reply to this email directly, view it on GitHub <#421 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AADSRCHUPM6UMQ3QA7U7EE3XIAOWLANCNFSM6AAAAAAYNUDLYE>. You are receiving this because you authored the thread.Message ID: ***@***.***>