Force editor to appear for an 'hg backout' if a message or logfile aren't supplied. Pre-fill the commit message with the changeset being backed out. Fixes bug 238.

#!/bin/sh

hg init a
echo a > a/a
hg --cwd a ci -A -m a
hg clone a b
echo b > b/b
hg --cwd b ci -A -m b
chmod 100 a/.hg
hg --cwd b push ../a
chmod 700 a/.hg