changelog: add a `branch` method, bypassing changectx
The only way to access the branch of a changeset is currently to
create a changectx object and access its `branch()` method. Creating
a new Python object is costly and has a huge impact on code doing
heavy access to `branch()` (like branchmap).
This change introduces a new method on changelog that allows direct
access to the branch of a revision. See the next changeset for impact.
http://mercurial.selenic.com/bts/issue842
$ hg init
$ echo foo > a
$ hg ci -Ama
adding a
$ hg up -r0000
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo bar > a
Should issue new head warning:
$ hg ci -Amb
adding a
created new head
$ hg up -r0000
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo stuffy > a
Should not issue new head warning:
$ hg ci -q -Amc
$ hg up -r0000
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo crap > a
$ hg branch testing
marked working directory as branch testing
(branches are permanent and global, did you want a bookmark?)
Should not issue warning:
$ hg ci -q -Amd