mq: improve qqueue message with patches applied (issue3036)

hgext/mq.py

@@ -3262,7 +3262,8 b' def qqueue(ui, repo, name=None, **opts):'
 
     def _setactive(name):
         if q.applied:
-            raise util.Abort(_('patches applied - cannot set new queue active'))
+            raise util.Abort(_('new queue created, but cannot make active '
+                               'as patches are applied'))
         _setactivenocheck(name)
 
     def _setactivenocheck(name):

tests/test-mq-qqueue.t

@@ -22,7 +22,7 b' Applied patches in default queue:'
 Try to change patch (create succeeds, switch fails):
 
   $ hg qqueue foo --create
-  abort: patches applied - cannot set new queue active
+  abort: new queue created, but cannot make active as patches are applied
   [255]
 
   $ hg qqueue
@@ -137,7 +137,7 b' Unapplied patches:'
 Fail switching back:
 
   $ hg qqueue patches
-  abort: patches applied - cannot set new queue active
+  abort: new queue created, but cannot make active as patches are applied
   [255]
 
 Fail deleting current: