On the default keybinding of Mod-Shift-Q, it is possible to press it by accident, closing all your work. This patch makes it so dwm will only exit if no windows are open.

You probably have various other "windows" open according to the X server; this includes not only a panel, but often also settings daemons, notification daemons, odd scripts, or other X utilities. As a result, you will probably need to consider changing EMPTY_WINDOW_COUNT to a number that works best for you. You can get a list of open X windows with xwininfo -tree -root. The command xwininfo -tree -root | grep child | head -1 with an empty desktop should get you most of the way there (although of course your terminal is open). Be prepared to recompile a few times to test!

Version two adds an override shortcut as Ctrl-Mod-Shift-Q; this is obviously configurable in config.h. It also removes a useless allocation, which could even potentially be overflowed (sizeof(Window) > 1).