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.
All heads of branches will be stored in a new cache file 'branchheads.cache'
within the .hg directory. The old 'branch.cache' file from older versions
will be ignored.
The new cache contents are formatted line-by-line as '{node} {branchtag}\n'.
This is the same as the previous format. Now, every head is recorded in
an oldest -> tipmost order.
The localrepo.branchheads function is reworked to use the data from the cache.
This should avoid a bad performance problem when the branch cache is
not up-to-date, and hgweb can't write an updated version because it
lacks permissions.
- hg tip doesn't use the branch cache; use hg log -r in its place
- commit doesn't use a HG_MERGE environment variable
- change the dates from "0 0" to "1000000 0"
