From a bug report: in the irregularly
shaped temple on the C quest home level (the room where the leader is
located), the lit south wall contained a dark spot where a secret door
is located. It stayed blank until you got right next to it rather than
just until you got to a good angle facing it. (Magic mapping hides the
problem by showing that spot as a wall instead of leaving it as unseen;
you have to walk or teleport to that room in order to see the problem.)
The code that lights walls and doors which border lit rooms neglected
temporary walls produced by secret doors.
6e07a2ffe1