--- a/mercurial/destutil.py	Tue Mar 08 04:08:33 2016 -0800
+++ b/mercurial/destutil.py	Mon Mar 07 03:14:19 2016 +0900
@@ -88,30 +88,55 @@
     return node, movemark, activemark
 
 def _destupdatebranch(repo, clean, check):
-    """decide on an update destination from current branch"""
+    """decide on an update destination from current branch
+
+    This ignores closed branch heads.
+    """
     wc = repo[None]
     movemark = node = None
     currentbranch = wc.branch()
     if currentbranch in repo.branchmap():
-        heads = repo.branchheads(currentbranch, closed=True)
+        heads = repo.branchheads(currentbranch)
         if heads:
             node = repo.revs('max(.::(%ln))', heads).first()
         if bookmarks.isactivewdirparent(repo):
             movemark = repo['.'].node()
     else:
         if currentbranch == 'default': # no default branch!
-            node = repo.lookup('tip') # update to tip
+            # update to the tipmost non-closed branch head
+            node = repo.revs('max(head() and not closed())').first()
         else:
             raise error.Abort(_("branch %s not found") % currentbranch)
     return node, movemark, None
 
+def _destupdatebranchfallback(repo, clean, check):
+    """decide on an update destination from closed heads in current branch"""
+    wc = repo[None]
+    currentbranch = wc.branch()
+    movemark = None
+    if currentbranch in repo.branchmap():
+        # here, all descendant branch heads are closed
+        heads = repo.branchheads(currentbranch, closed=True)
+        assert heads, "any branch has at least one head"
+        node = repo.revs('max(.::(%ln))', heads).first()
+        assert node is not None, ("any revision has at least "
+                                  "one descendant branch head")
+        if bookmarks.isactivewdirparent(repo):
+            movemark = repo['.'].node()
+    else:
+        # here, no "default" branch, and all branches are closed
+        node = repo.lookup('tip')
+        assert node is not None, "'tip' exists even in empty repository"
+    return node, movemark, None
+
 # order in which each step should be evalutated
 # steps are run until one finds a destination
-destupdatesteps = ['evolution', 'bookmark', 'branch']
+destupdatesteps = ['evolution', 'bookmark', 'branch', 'branchfallback']
 # mapping to ease extension overriding steps.
 destupdatestepmap = {'evolution': _destupdateobs,
                      'bookmark': _destupdatebook,
                      'branch': _destupdatebranch,
+                     'branchfallback': _destupdatebranchfallback,
                      }
 
 def destupdate(repo, clean=False, check=False):
@@ -362,8 +387,27 @@
     heads = repo.branchheads(currentbranch)
     if repo.revs('%ln and parents()', allheads):
         # we are on a head, even though it might be closed
+        #
+        #  on closed otherheads
+        #  ========= ==========
+        #      o        0       all heads for current branch are closed
+        #               N       only descendant branch heads are closed
+        #      x        0       there is only one non-closed branch head
+        #               N       there are some non-closed branch heads
+        #  ========= ==========
         otherheads = repo.revs('%ln - parents()', heads)
-        if otherheads:
+        if repo['.'].closesbranch():
+            ui.status(_('updated to a closed branch head, '
+                        'because all descendant heads are closed.\n'
+                        'beware of re-opening closed head '
+                        'by subsequent commit here.\n'))
+            if otherheads:
+                ui.status(_('%i other heads for branch "%s"\n') %
+                          (len(otherheads), currentbranch))
+            else:
+                ui.status(_('all heads for branch "%s" are closed.\n') %
+                          currentbranch)
+        elif otherheads:
             ui.status(_('%i other heads for branch "%s"\n') %
                       (len(otherheads), currentbranch))
 

--- a/tests/test-bookmarks-current.t	Tue Mar 08 04:08:33 2016 -0800
+++ b/tests/test-bookmarks-current.t	Mon Mar 07 03:14:19 2016 +0900
@@ -202,3 +202,22 @@
   Z
   $ hg log -T '{bookmarks % "{active}\n"}' -r Z
   Z
+
+test that updating to closed branch head also advances active bookmark
+
+  $ hg commit --close-branch -m "closed"
+  $ hg update -q ".^1"
+  $ hg bookmark Y
+  $ hg bookmarks
+     X                         3:4d6bd4bfb1ae
+   * Y                         3:4d6bd4bfb1ae
+     Z                         0:719295282060
+  $ hg update
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updating bookmark Y
+  $ hg bookmarks
+     X                         3:4d6bd4bfb1ae
+   * Y                         4:8fa964221e8e
+     Z                         0:719295282060
+  $ hg parents -q
+  4:8fa964221e8e

--- a/tests/test-update-branches.t	Tue Mar 08 04:08:33 2016 -0800
+++ b/tests/test-update-branches.t	Mon Mar 07 03:14:19 2016 +0900
@@ -186,28 +186,111 @@
 Test updating if at least one non-closed branch head exists
 
 if on the closed branch head:
-- updating is no-op
+- update to "."
+- "updated to a closed branch head ...." message is displayed
 - "N other heads for ...." message is displayed
 
   $ hg update -q -C 3
   $ hg commit --close-branch -m 6
   $ norevtest "on closed branch head" clean 6
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to a closed branch head, because all descendant heads are closed.
+  beware of re-opening closed head by subsequent commit here.
+  1 other heads for branch "default"
+  parent=6
+
+if descendant non-closed branch head exists, and it is only one branch head:
+- update to it, even if its revision is less than closed one
+- "N other heads for ...." message isn't displayed
+
+  $ norevtest "non-closed 2 should be chosen" clean 1
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  parent=2
+
+if all descendant branch heads are closed, but there is another branch head:
+- update to the tipmost descendant head
+- "updated to a closed branch head ...." message is displayed
+- "N other heads for ...." message is displayed
+
+  $ norevtest "all descendant branch heads are closed" clean 3
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to a closed branch head, because all descendant heads are closed.
+  beware of re-opening closed head by subsequent commit here.
   1 other heads for branch "default"
   parent=6
 
 Test updating if all branch heads are closed
 
 if on the closed branch head:
-- updating is no-op
-- "N other heads for ...." message isn't displayed
+- update to "."
+- "updated to a closed branch head ...." message is displayed
+- "all heads of branch ...." message is displayed
 
   $ hg update -q -C 2
   $ hg commit --close-branch -m 7
   $ norevtest "all heads of branch default are closed" clean 6
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to a closed branch head, because all descendant heads are closed.
+  beware of re-opening closed head by subsequent commit here.
+  all heads for branch "default" are closed.
   parent=6
 
+if not on the closed branch head:
+- update to the tipmost descendant (closed) head
+- "updated to a closed branch head ...." message is displayed
+- "all heads of branch ...." message is displayed
+
+  $ norevtest "all heads of branch default are closed" clean 1
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to a closed branch head, because all descendant heads are closed.
+  beware of re-opening closed head by subsequent commit here.
+  all heads for branch "default" are closed.
+  parent=7
+
+  $ cd ..
+
+Test updating if "default" branch doesn't exist and no revision is
+checked out (= "default" is used as current branch)
+
+  $ hg init no-default-branch
+  $ cd no-default-branch
+
+  $ hg branch foobar
+  marked working directory as branch foobar
+  (branches are permanent and global, did you want a bookmark?)
+  $ echo a > a
+  $ hg commit -m "#0" -A
+  adding a
+  $ echo 1 >> a
+  $ hg commit -m "#1"
+  $ hg update -q 0
+  $ echo 3 >> a
+  $ hg commit -m "#2"
+  created new head
+  $ hg commit --close-branch -m "#3"
+
+if there is at least one non-closed branch head:
+- update to the tipmost branch head
+
+  $ norevtest "non-closed 1 should be chosen" clean null
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  parent=1
+
+if all branch heads are closed
+- update to "tip"
+- "updated to a closed branch head ...." message is displayed
+- "all heads for branch "XXXX" are closed" message is displayed
+
+  $ hg update -q -C 1
+  $ hg commit --close-branch -m "#4"
+
+  $ norevtest "all branches are closed" clean null
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to a closed branch head, because all descendant heads are closed.
+  beware of re-opening closed head by subsequent commit here.
+  all heads for branch "foobar" are closed.
+  parent=4
+
   $ cd ../b1
 
 Test obsolescence behavior