Fixed by http://hg.intevation.org/mercurial/crew/rev/d8d0fc3988ca
(color/progress: subclass ui instead of using wrapfunction (issue2096))

I've posted a potential fix on the mailing list here: 
http://www.selenic.com/pipermail/mercurial-devel/2010-July/022423.html

(Doing more research.)

On default/1.6 the problem is similar but slightly different. The color 
extension isn't using pushbuffer or popbuffer to capture output, but it is 
wrapping popbuffer, write, and write_err on ui to provide colorization. The 
copied ui that mqcommand() uses doesn't retain these wrappers.

Also relevant: http://selenic.com/hg/rev/2e8926e9cc32

Or more precisely:

1. _colorstatuslike() calls ui.pushbuffer()
2. _colorstatuslike() calls mqcommand()
3. mqcommand() calls repo.mq.qrepo()
4. localrepo.__init__() copies ui and assigns it to qrepo.ui
5. mqcommand calls status() with this new ui object
6. _colorstatuslike() calls ui.popbuffer() and gets nothing back. status() 
wrote to the copied ui instead of the original one.

The ui object in _colorstatuslike() is not the ui object being written to; 
pushing and popping its buffer gets nothing back.

I added some print statements in mqcommand() and _colorstatuslike(). You can 
see the three ui objects:

in _colorstatuslike():
    ui: <mercurial.ui.ui object at 0x82e77cc> [a]
    repo: <hgext.mq.mqrepo object at 0x82f26ec> [b]
    repo.ui: <mercurial.ui.ui object at 0x82e77cc> [b]
in mqcommand():
    ui: <mercurial.ui.ui object at 0x82e77cc> [a]
    repo: <hgext.mq.mqrepo object at 0x82f26ec> [b]
    repo.ui: <mercurial.ui.ui object at 0x82e77cc> [b]
    r: <hgext.mq.mqrepo object at 0x82fa98c> [c]
    r.ui: <mercurial.ui.ui object at 0x82faa4c> [c]

Because color is wrapping mqcommand and not status directly, it never sees 
[c], so push/popbuffer doesn't collect anything.

I'm not sure what the best fix would be.

When both mq and the color extension are used, the output of commands
wrapped by mqcommand is not colorized, as demonstrated by the following script.


#!/bin/sh

cat <<EOF >test.hgrc
[ui]
username=foo@bar
[extensions]
color=
mq=
EOF
export HGRCPATH="$(pwd)/test.hgrc"

rm -rf testrepo
hg init testrepo
cd testrepo
hg init --mq
hg qnew foo
touch bar
echo "% status on main repo (colorized)"
hg stat
echo "% status on queue repo (not colorized)"
hg stat --mq