# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@ens-lyon.org>
# Date 2016-12-12 12:32:45
# Node ID b52e8a4f4c0fa1a206a3f181b250ba9833fe88a1
# Parent  07025bd744a09dd5622e16ccef11966fda7b86f2

registrar: raise a programming error on duplicated registering

Previous, registering different object with the same name would silently
overwrite the first value with the second one. We now detect the situation and
raise an error. No extension in test or core had the issues.

diff --git a/mercurial/registrar.py b/mercurial/registrar.py
--- a/mercurial/registrar.py
+++ b/mercurial/registrar.py
@@ -8,6 +8,7 @@
 from __future__ import absolute_import
 
 from . import (
+    error,
     pycompat,
     util,
 )
@@ -50,6 +51,10 @@ class _funcregistrarbase(object):
     def _doregister(self, func, decl, *args, **kwargs):
         name = self._getname(decl)
 
+        if name in self._table:
+            msg = 'duplicate registration for name: "%s"' % name
+            raise error.ProgrammingError(msg)
+
         if func.__doc__ and not util.safehasattr(func, '_origdoc'):
             doc = func.__doc__.strip()
             func._origdoc = doc