cat: default to working dir parent instead of tip
This introduces a defaultrev function that chooses
the working dir parent if a revision isn't specified,
and uses it in several places.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "extdiff=" >> $HGRCPATH
hg init a
cd a
echo a > a
hg add
diff -N /dev/null /dev/null 2> /dev/null
if [ $? -ne 0 ]; then
opt="-p gdiff"
fi
hg extdiff -o -Nr $opt
echo "[extdiff]" >> $HGRCPATH
echo "cmd.falabala=echo" >> $HGRCPATH
echo "opts.falabala=diffing" >> $HGRCPATH
hg falabala
hg help falabala
hg ci -d '0 0' -mtest1
echo b >> a
hg ci -d '1 0' -mtest2
hg falabala -r 0:1 || echo "diff-like tools yield a non-zero exit code"