[PATCH 1 of 2] revset: add support for branch(wdir()) and wdir() & branch()

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1471684519 -32400
#      Sat Aug 20 18:15:19 2016 +0900
# Node ID 8a92c8414acdf0b72195ed393cc22717e0e80acf
# Parent  9d201b39ccd91b7be2eeb277b1b0ae6964bafeeb
revset: add support for branch(wdir()) and wdir() & branch()

diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -474,6 +474,11 @@ def branch(repo, subset, x):
     :hg:`help revisions.patterns`.
     """
     getbi = repo.revbranchcache().branchinfo
+    def getbranch(r):
+        try:
+            return getbi(r)[0]
+        except error.WdirUnsupported:
+            return repo[r].branch()
 
     try:
         b = getstring(x, '')
@@ -486,21 +491,21 @@ def branch(repo, subset, x):
             # note: falls through to the revspec case if no branch with
             # this name exists and pattern kind is not specified explicitly
             if pattern in repo.branchmap():
-                return subset.filter(lambda r: matcher(getbi(r)[0]),
+                return subset.filter(lambda r: matcher(getbranch(r)),
                                      condrepr=('<branch %r>', b))
             if b.startswith('literal:'):
                 raise error.RepoLookupError(_("branch '%s' does not exist")
                                             % pattern)
         else:
-            return subset.filter(lambda r: matcher(getbi(r)[0]),
+            return subset.filter(lambda r: matcher(getbranch(r)),
                                  condrepr=('<branch %r>', b))
 
     s = getset(repo, fullreposet(repo), x)
     b = set()
     for r in s:
-        b.add(getbi(r)[0])
+        b.add(getbranch(r))
     c = s.__contains__
-    return subset.filter(lambda r: c(r) or getbi(r)[0] in b,
+    return subset.filter(lambda r: c(r) or getbranch(r) in b,
                          condrepr=lambda: '<branch %r>' % sorted(b))
 
 @predicate('bumped()', safe=True)
diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -1294,6 +1294,35 @@ Test working-directory integer revision 
   $ hg debugrevspec '0:wdir() & id(ffffffffffff)'
 BROKEN: should be '2147483647'
 
+Test branch() with wdir()
+
+  $ log '0:wdir() & branch("literal:é")'
+  8
+  9
+  2147483647
+  $ log '0:wdir() & branch("re:é")'
+  8
+  9
+  2147483647
+  $ log '0:wdir() & branch("re:^a")'
+  0
+  2
+  $ log '0:wdir() & branch(8)'
+  8
+  9
+  2147483647
+
+branch(wdir()) returns all revisions belonging to the working branch. The wdir
+itself isn't returned unless it is explicitly populated.
+
+  $ log 'branch(wdir())'
+  8
+  9
+  $ log '0:wdir() & branch(wdir())'
+  8
+  9
+  2147483647
+
   $ log 'outgoing()'
   8
   9