This is from the pull request for the assertion failure fix. It
did not mention how to reproduce the assertion failure, just added
casts to a bunch of isspace/isprint/tolower calls that didn't already
have such.
I removed an obsolete change for win/tty/topl.c and changed the
win/win32/mswproc.c code to avoid using an expression with side-effects
(*colorstring++) in calls to tolower() in case someone overrides that
with a macro which evaluates its argument more than once as some pre-
ANSI ones used to do. Not tested, might have typos....
sys/wince/*.c still needs similar casts.