commands: add more robust support for 'hg log -b' (issue2078)

Fixes issue2078 and adds tests to cover various 'hg log -b' uses.

This change adds a localrepo.lookupbranch(key, remote=None) function. This
will look up the branch of the revision with the given key. The algorithm
works like this:

    * If a remote repo is given and KEY is the name of a branch in that repo,
      return KEY.
    * If no remote repo is given and KEY is the name of a branch in the local
      repo object, return KEY.
    * Otherwise look up the revision with the identifier KEY in the local repo
      and return its branch.

This change also makes 'hg log -b' use this new functionality and adds a few
tests for it.

mercurial/commands.py

@@ -2160,6 +2160,7 b' def log(ui, repo, *pats, **opts):'
         df = util.matchdate(opts["date"])
 
     opts['branch'] += opts.get('only_branch')
+    opts['branch'] = [repo.lookupbranch(b) for b in opts['branch']]
 
     displayer = cmdutil.show_changeset(ui, repo, opts, True, matchfn)
     def prep(ctx, fns):

mercurial/localrepo.py

@@ -455,6 +455,14 b' class localrepository(repo.repository):'
             pass
         raise error.RepoLookupError(_("unknown revision '%s'") % key)
 
+    def lookupbranch(self, key, remote=None):
+        repo = remote or self
+        if key in repo.branchmap():
+            return key
+
+        repo = (remote and remote.local()) and remote or self
+        return repo[key].branch()
+
     def local(self):
         return True
 

tests/test-log

@@ -162,7 +162,19 b' hg log -b test'
 echo '% log -b dummy'
 hg log -b dummy
 
+echo '% log -b .'
+hg log -b .
+
 echo '% log -b default -b test'
 hg log -b default -b test
 
+echo '% log -b default -b .'
+hg log -b default -b .
+
+echo '% log -b . -b test'
+hg log -b . -b test
+
+echo '% log -b 2'
+hg log -b 2
+
 exit 0

tests/test-log.out

@@ -360,6 +360,22 b' date: Thu Jan 01 00:00:00 1970 +0'
 summary:     commit on test
 
 % log -b dummy
+abort: unknown revision 'dummy'!
+% log -b .
+changeset:   3:f5d8de11c2e2
+branch:      test
+tag:         tip
+parent:      1:d32277701ccb
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on test
+
+changeset:   1:d32277701ccb
+branch:      test
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on test
+
 % log -b default -b test
 changeset:   3:f5d8de11c2e2
 branch:      test
@@ -386,3 +402,56 b' user: test'
 date:        Thu Jan 01 00:00:00 1970 +0000
 summary:     commit on default
 
+% log -b default -b .
+changeset:   3:f5d8de11c2e2
+branch:      test
+tag:         tip
+parent:      1:d32277701ccb
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on test
+
+changeset:   2:c3a4f03cc9a7
+parent:      0:24427303d56f
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on default
+
+changeset:   1:d32277701ccb
+branch:      test
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on test
+
+changeset:   0:24427303d56f
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on default
+
+% log -b . -b test
+changeset:   3:f5d8de11c2e2
+branch:      test
+tag:         tip
+parent:      1:d32277701ccb
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on test
+
+changeset:   1:d32277701ccb
+branch:      test
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on test
+
+% log -b 2
+changeset:   2:c3a4f03cc9a7
+parent:      0:24427303d56f
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on default
+
+changeset:   0:24427303d56f
+user:        test
+date:        Thu Jan 01 00:00:00 1970 +0000
+summary:     commit on default
+