diff -r cd235d6f851b -r d3d35a55e03b mercurial/chgserver.py
--- a/mercurial/chgserver.py	Sat Nov 11 16:46:41 2017 +0900
+++ b/mercurial/chgserver.py	Sat Nov 11 17:55:15 2017 +0900
@@ -235,6 +235,7 @@
     cwds = dispatch._earlygetopt(['--cwd'], args)
     cwd = cwds and os.path.realpath(cwds[-1]) or None
     rpath = dispatch._earlygetopt(["-R", "--repository", "--repo"], args)
+    rpath = rpath and rpath[-1] or ''
     path, newlui = dispatch._getlocal(newui, rpath, wd=cwd)
 
     return (newui, newlui)