There was no provision for malloc() potentially returning Null and it
wasn't integrated with nethack's MONITOR_HEAP. 'heaputil' shows that
the curses interface is leaking like a sieve. If some things are
actually being allocated separately and then freed from within curses,
those need to be thoroughly documented and maybe switched back to
malloc().
The curses interface already has a hack to keep 'Count: 12', 'Count:
123' intermediate multi-digit counts out of its message recall history
for ^P, but it was flushing real messages when getpos()'s 'autodescribe'
reported what the cursor moved over. Overload the count hack to support
putstr(WIN_MESSAGE, ATR_NOHISTORY, text)
(which is what custompline(SUPPRESS_HISTORY, ...) eventually calls).
The conditional logic for when to create the 'count_window' was pretty
convoluted. This simplification has the same semantics but I don't
have PDCURSES to actually verify that.
