Marble-qt windowing issue & external_rules_command

[intr-cx]

First off, thank you for creating what has been my trusty window manager for years now.

I've been experiencing a strange issue launching Marble-qt. After launching, it would spawn a window, which is promptly frozen and detached from the rest of the stack. This window stays in the foreground and persists between desktops, obscuring a portion of the screen. Closing Marble-qt will remove this window again.

Upon further inspection, the issue is reproducible with Bspwm and a blank config. The same issue also exists on Dwm, except that Dwm still manages the window.

@Darukutsu figured out that setting the config value external_rules_command to any value (doesn't have to be an existing executable file) makes the issue go away.

bspwm version: 0.9.10
Marble-qt version: 24.05.2
Distro: Artix Linux

[ortango]

marble-qt seems to create and destroy 2 windows before the actual window is spawned.
what seems to be going on is that running right into manage_window() when e_r_c is null causes bspwm to manage a window that is about to be destroyed when the main loop processes xcb events.

when e_r_c is not null it delegates manage_window to the next main loop with add_pending_rule. that should cause unmap_notify to remove the pending rule before it's mapped (i think). i wonder if there is a side effect of using this for e_r_c == n