tests/notcapable

rhg: in path_encode, split Dest into VecDest and MeasureDest

Two separate types make the write semantics easier to understand
because we can consider the two sinks separately.

Having two independent compiled functions for size measurement
and for actual encoding seems likely to improve performance, too.
(and maybe we should get rid of measurement altogether)

Getting rid of [Dest] also removes the ugly option rewrapping
code, which is good.

# Disable the $CAP wire protocol capability.

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

cat > notcapable-$CAP.py << EOF
from mercurial import extensions, localrepo
from mercurial.interfaces import repository
def extsetup(ui):
    extensions.wrapfunction(repository.peer, 'capable', wrapcapable)
    extensions.wrapfunction(localrepo.localrepository, 'peer', wrappeer)
def wrapcapable(orig, self, name, *args, **kwargs):
    if name in b'$CAP'.split(b' '):
        return False
    return orig(self, name, *args, **kwargs)
def wrappeer(orig, self, path=None):
    # Since we're disabling some newer features, we need to make sure local
    # repos add in the legacy features again.
    return localrepo.locallegacypeer(self, path=path)
EOF

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