Store empty (default) branch in branch cache, too.
Operations on this branch don't work otherwise.
Reading branches.cache had to be adjusted to allow an empty label.
Adjusted reading of the cache tip for symmetry, no functional change here.
#!/bin/sh
echo '# basic operation'
hg init basic
cd basic
echo a > a
hg commit -d '0 0' -A -m a
echo b >> a
hg commit -d '1 0' -m b
hg backout -d '2 0' tip
cat a
echo '# file that was removed is recreated'
cd ..
hg init remove
cd remove
echo content > a
hg commit -d '0 0' -A -m a
hg rm a
hg commit -d '1 0' -m b
hg backout -d '2 0' --merge tip
cat a
echo '# backout of backout is as if nothing happened'
hg backout -d '3 0' --merge tip
cat a 2>/dev/null || echo cat: a: No such file or directory
echo '# backout with merge'
cd ..
hg init merge
cd merge
echo line 1 > a
hg commit -d '0 0' -A -m a
echo line 2 >> a
hg commit -d '1 0' -m b
echo line 3 >> a
hg commit -d '2 0' -m c
hg backout --merge -d '3 0' 1
hg commit -d '4 0' -m d
cat a
echo '# backout should not back out subsequent changesets'
hg init onecs
cd onecs
echo 1 > a
hg commit -d '0 0' -A -m a
echo 2 >> a
hg commit -d '1 0' -m b
echo 1 > b
hg commit -d '2 0' -A -m c
hg backout -d '3 0' 1
hg locate b
cd ..
hg init m
cd m
echo a > a
hg commit -d '0 0' -A -m a
echo b > b
hg commit -d '1 0' -A -m b
echo c > c
hg commit -d '2 0' -A -m b
hg update 1
echo d > d
hg commit -d '3 0' -A -m c
hg merge 2
hg commit -d '4 0' -A -m d
echo '# backout of merge should fail'
hg backout 4
echo '# backout of merge with bad parent should fail'
hg backout --parent 0 4
echo '# backout of non-merge with parent should fail'
hg backout --parent 0 3
echo '# backout with valid parent should be ok'
hg backout -d '5 0' --parent 2 4
hg rollback
hg update -C
hg backout -d '6 0' --parent 3 4
exit 0