Keep track of remote branch heads in Mercurial.

With this extension installed, Mercurial gains one new feature: when you pull from a repository listed in .hg/hgrc's [paths] section, you get output similar to the following:

@  3[tip]   7c2fd3b9020c   2009-04-27 18:04 -0500   durin42
|    Add delta
o  2[default/default]   030b686bedc4   2009-04-27 18:04 -0500   durin42
|    Add gamma
o  1[stable/default]   c561b4e977df   2009-04-27 18:04 -0500   durin42
|    Add beta
o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
     Add alpha

What this output is showing is that the head of the default branch in a repo at path stable is c561b4e977df, and the head of default in the repo at path default is at 030b686bedc4. This is accomplished by sending a single extra request to the Mercurial server after the pull is complete. The nature of this request (branchheads) requires that the server be Mercurial 1.3 or newer.

This extension should work properly with paths from the schemes extension included with Mercurial 1.4 and later. Other extensions which perform varying kinds of manipulation on the repository path may not function as expected.

When revsets are available (Mercurial 1.7 and later), remotebranches makes three new revsets available: pushed(), upstream() and remotebranches(). The pushed() revset returns all revisions that are have been pushed to any repository tracked by remotebranches. The upstream() set is those revisions which are in a repository whose path is listed in the upstream field of the [remotebranches] configuration section. If there is no remotebranches.upstream setting, it defaults to behaving identically to pushed(). The remotebranches() revset simply returns all remote branches head changesets.

When template keywords can be registered (Mercurial 1.5 and later), remotebranches adds a remotebranches keyword returning a space separated list of all names of remote branches heads on a changeset.