I managed to restore the old behavior after poking around the 3.2 code and seeing how it handled the "remember torch-lit grids" option. I edited function cave_note_spot in cave.c and changed this line:
Code:
/* Memorize this grid */
c->info[y][x] |= (CAVE_MARK);
to this:
Code:
/* Memorize this grid */
if (c->feat[y][x] > FEAT_INVIS || (c->info[y][x] & CAVE_GLOW))
c->info[y][x] |= (CAVE_MARK);
I am OK with doing it for myself if there is not enough interest in changing it for everyone, but I wanted to put the question out there to see if anyone else wanted it. I found it disorienting because corridors looked "lit up" but unseen monsters would cast/throw/fire at you or pop into view to melee you.