Correct optimization from 3464f5e77f34; add a test.
If there are two (or more) heads that point to the same .hgtags
node, we can safely skip parsing the file in all but the last head.
(In 3464f5e77f34, we were parsing the file in the first head and
skipping all the others.)
#!/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
# test diff during merge
hg update 0
echo b >> b
hg add b
hg ci -m "new branch" -d '1 0'
hg update -C 1
hg merge tip
hg falabala || echo "diff-like tools yield a non-zero exit code"