Branch heads should not include "heads" that are ancestors of other heads.
For example, given 1 (branch a) -> 2 (branch b) -> 3 (branch a)
I expect "hg heads a" to show only 3.
Discovered by running hg heads HEAD on the mutt repo, where older clients
committed default on top of HEAD.
#!/bin/sh
hg init
touch unknown
touch a
hg add a
hg ci -m "1" -d "1000000 0"
touch b
hg add b
hg ci -m "2" -d "1000000 0"
echo %% Should show unknown
hg status
hg revert -r 0 --all
echo %% Should show unknown and b removed
hg status
echo %% Should show a and unknown
ls