bookmarks: deactivate current bookmark if no name is given

f57f891eb88e added this help text to hg bookmark:

  If no NAME is given, the current active bookmark will be marked inactive.

But that was never actually the case.

Originally spotted by Idan Kamara <[e-mail]>.

mercurial/commands.py

@@ -846,6 +846,12 b' def bookmark(ui, repo, mark=None, rev=No'
             raise util.Abort(_("bookmark name required"))
         if len(marks) == 0:
             ui.status(_("no bookmarks set\n"))
+        if inactive:
+            if not repo._bookmarkcurrent:
+                ui.status(_("no active bookmark\n"))
+            else:
+                bookmarks.setcurrent(repo, None)
+            return
         else:
             for bmark, n in sorted(marks.iteritems()):
                 current = repo._bookmarkcurrent

tests/test-bookmarks-current.t

@@ -115,6 +115,13 b' deactivate current bookmark using -i'
      Z                         0:719295282060
 
   $ hg up -q Y
+  $ hg bookmark -i
+  $ hg bookmarks
+     Y                         0:719295282060
+     Z                         0:719295282060
+  $ hg bookmark -i
+  no active bookmark
+  $ hg up -q Y
   $ hg bookmarks
    * Y                         0:719295282060
      Z                         0:719295282060