Don't decode unicode strings.
This does not work with python2.3 and is probably not useful anyway with 2.4.
#!/bin/sh
#
hg init t
cd t
echo 1 > foo
hg ci -Am m
cd ..
hg clone t tt
cd tt
echo 1.1 > foo
hg ci -Am m
cd ../t
echo 1.2 > foo
hg ci -Am m
echo % should fail
hg pull -u ../tt
cd ../tt
echo % should fail
hg pull -u ../t
HGMERGE=true hg merge
hg ci -mm
cd ../t
echo % should work
hg pull -u ../tt