tests/notcapable

hgweb: make "comparison" get parent from not filelog but changelog

Before this patch, "comparison" shows unexpected result, when the
specified file is not modified in the specified revision, even though
"diff" shows empty result.

When REV doesn't change specified FILE, "diff" shows:

  "hg diff -c REV FILE"

but "comparison" shows:

  "hg diff -c `hg parents -r REV FILE` FILE"

In other words, the former gets parent from changelog, but the latter
gets one from filelog.

This may confuse users browsing (and switching "diff" and
"comparison" of) files in the specified revision.

This patch makes "comparison" get parent from not filelog but
changelog, to show "hg diff -c REV FILE" in both "diff" and
"comparison" pages.

# Disable the $CAP wire protocol capability.

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

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