Kotolegokot/minetest-mod-money — pull request #2 by hdastwb (2013-06-25 00:42:32+00:00)
Title: make buying stuff from nonexistent people not crash servers

as stated in the commit message:

Menche's server suffered a severe loss of playerdata that made all of the accounts on it invalidated until the respective players logged back on; since many have not yet, attempts to shop at the mall typically end in crashing the server and rolling back the map. This should fix that.