branch: abort if closing branch from a non-branchhead cset

This patch make sure that we abort if the user is trying to
close a branch from a cset which is not a branch head.
Changes in test file reflect the fixed behaviour.

Differential Revision: https://phab.mercurial-scm.org/D6282

mercurial/commands.py

@@ -1675,6 +1675,8 b' def _docommit(ui, repo, *pats, **opts):'
 
         if not bheads:
             raise error.Abort(_('can only close branch heads'))
+        elif branch == repo['.'].branch() and repo['.'].node() not in bheads:
+            raise error.Abort(_('can only close branch heads'))
         elif opts.get('amend'):
             if (repo['.'].p1().branch() != branch and
                 repo['.'].p2().branch() != branch):

tests/test-branches.t

@@ -956,19 +956,16 b' Test to make sure that `--close-branch` '
 
 trying to close branch from a cset which is not a branch head
 it should abort:
-XXX: it should have aborted here
   $ hg ci -m "closing branch" --close-branch
-  created new head
+  abort: can only close branch heads
+  [255]
 
   $ hg up 0
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg log -GT "{rev}: {node|short} {desc|firstline}\n\t{branch}\n\n"
-  _  3: 006876ddd20e closing branch
+  o  2: 155349b645be added c
   |  	default
   |
-  | o  2: 155349b645be added c
-  |/   	default
-  |
   o  1: 5f6d8a4bf34a added b
   |  	default
   |