mercurial/context.py

--- a/mercurial/context.py	Mon Apr 02 08:43:08 2018 -0700
+++ b/mercurial/context.py	Mon Apr 02 09:18:01 2018 -0700
@@ -411,9 +411,6 @@
         """changeid is a revision number, node, or tag"""
         super(changectx, self).__init__(repo)
 
-        if changeid == '':
-            changeid = '.'
-
         try:
             if isinstance(changeid, int):
                 self._node = repo.changelog.node(changeid)