largefiles: fix addremove when largefile is missing (
issue3227)
posix: workaround lack of TIOCGWINSZ on Irix (
issue3449)
On an Irix 6.5.24 system, TIOCGWINSZ is not available. This means that
any usage of the "hg" tool that looks up the terminal size (e.g. "hg
help") will fail with an AttributeError.
A simple work-around is just to wrap this block in mercurial/posix.py
with a try/except so that it ends up using the default 80 characters
width.