convert: save hg revision during a convert
This breaks hg->hg hash roundtripping, but that was fragile, didn't work
reliably, and hence arguably of little value.
#!/bin/sh
# test command parsing and dispatch
hg init a
cd a
echo a > a
hg ci -Ama -d '0 0'
echo "# missing arg"
hg cat
echo '% [defaults]'
hg cat a
cat >> $HGRCPATH <<EOF
[defaults]
cat = -v
EOF
hg cat a
echo '% no repo'
cd ..
hg cat
exit 0