Prevent extremely long command line arguments from overflowing local
buffers in raw_printf or config_error_add. The increased buffer
sizes they recently got to deal with long configuration file values
aren't sufficient to handle command line induced overflows.
choose_windows(core): copy and truncate the window_type argument in
case it gets passed to config_error_add().
process_options(unix): report bad values with "%.60s" so that vsprintf
will implicitly truncate when formatted by raw_printf().
Fix 'Bugs 4, 5, and 6' which all use a similar fix but would have
conflicts over '#define BIGBUFSZ' if committed separately.
Format ("short explanation %s", string_argument), where the
explanation always has modest length but the string is potentially
up to 4*BUFSZ in length, into a 5*BUFSZ buffer. Then truncate the
result to at most BUFSZ-1 characters so that it can be safely passed
to interface-specific putstr() or raw_print().
Applies to pline(), raw_printf(), and config_error_add(). Also done
for impossible() although there's no evidence that its buffer could
be overflowed in a controlled manner.
Fix 'Bug 3' where too long SYMBOL=string in run-time config file could
overflow a local buffer and clobber the stack.
Valid value is only one character long after processing an 'escaped'
encoded character which can be at most 6 characters (plus terminator):
backslash M backslash and up three digits. If/when UTF8 gets added
the number of digits will increase. Use a truncated copy of the input
(substantially bigger than 6+1); ignore any excess.
Fix 'Bug 2' where too long MENUCOLOR=string in run-time config file
could overflow a local buffer and clobber the stack.
Theoretically a menu coloring regular expression could require a
bigger buffer but I don't think we need to try to support that.
255 characters minus the amount needed to specify color and/or
attributes should be ample.
have string_for_opt() return the value string or empty_optstr to
provide some level of crash protection if some future added option
processing misbehaves. Callers of string_for_opt() and
string_for_env_opt() should always check for a match to empty_optstr.
Poly'd hero hiding on the ceiling was told "you can't go down here"
if using '>' at a spot that didn't have down stairs, trap door, hole,
or pit. Let '>' bring a ceiling hider out of hiding; lurker above
resumes flying, piercer falls to floor or whatever is underneath it.
Fix some issues noticed when experimenting with ceiling hiders.
They're all blind (at least without the monks' Eyes) and some of
the behavior while blind seemed to be incorrect (though some that
I thought was wrong turned out to be ok; feel_newsym() won't update
the map if the hero can't reach the floor). Fixing that made me
notice that some terrain side-effects (being underwater or stuck in
lava) weren't getting disabled when the underlying terrain wasn't
the corresponding type anymore.
