tests/notcapable

ui: remove unreachable branches and function calls from write() (issue6059)

This is at least faster than ui.write() of 4.8.2.

  $ HGRCPATH=/dev/null hg files -R mozilla-central --time >/dev/null
  4.8.2:  time: real 2.340 secs (user 2.310+0.000 sys 0.020+0.000)
  4.9rc0: time: real 2.580 secs (user 2.550+0.000 sys 0.020+0.000)
  this:   time: real 2.230 secs (user 2.210+0.000 sys 0.020+0.000)

Maybe the formatter should own a resolved write() function because it will
just call dest.write(msg) most of the time, but that would be too much for
stable.

# Disable the $CAP wire protocol capability.

if test -z "$CAP"
then
    echo "CAP environment variable not set."
fi

cat > notcapable-$CAP.py << EOF
from mercurial import extensions, localrepo, repository
def extsetup(ui):
    extensions.wrapfunction(repository.peer, 'capable', wrapcapable)
    extensions.wrapfunction(localrepo.localrepository, 'peer', wrappeer)
def wrapcapable(orig, self, name, *args, **kwargs):
    if name in '$CAP'.split(' '):
        return False
    return orig(self, name, *args, **kwargs)
def wrappeer(orig, self):
    # Since we're disabling some newer features, we need to make sure local
    # repos add in the legacy features again.
    return localrepo.locallegacypeer(self)
EOF

echo '[extensions]' >> $HGRCPATH
echo "notcapable-$CAP = `pwd`/notcapable-$CAP.py" >> $HGRCPATH