tests/notcapable

exchange: move narrow acl functionality into core

This function is called by the custom changegroup generation code
in the narrow extension. I want to move that changegroup code into
core. That means we need to move this function.

The code is kinda hacky in that assumes existence of REMOTE_USER,
which is only present on authenticated HTTP requests. I've added
a comment indicating that.

Differential Revision: https://phab.mercurial-scm.org/D4008

# Disable the $CAP wire protocol capability.

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

cat > notcapable-$CAP.py << EOF
from mercurial import extensions, localrepo, repository
def extsetup():
    extensions.wrapfunction(repository.peer, 'capable', wrapcapable)
    extensions.wrapfunction(localrepo.localrepository, 'peer', wrappeer)
def wrapcapable(orig, self, name, *args, **kwargs):
    if name in '$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