[PATCH 3 of 7] py3: drop b'' while formatting ResponseError

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1531043891 -32400
#      Sun Jul 08 18:58:11 2018 +0900
# Node ID 6737fa60496004cfb6a9bc1bbc1e212321c97591
# Parent  87079f4958b2a73c84d1a6339801854b5245ee0e
py3: drop b'' while formatting ResponseError

diff --git a/contrib/python3-whitelist b/contrib/python3-whitelist
--- a/contrib/python3-whitelist
+++ b/contrib/python3-whitelist
@@ -36,6 +36,7 @@ test-bundle-r.t
 test-bundle-type.t
 test-bundle-vs-outgoing.t
 test-bundle.t
+test-bundle2-exchange.t
 test-bundle2-multiple-changegroups.t
 test-bundle2-pushback.t
 test-cappedreader.py
diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -201,7 +201,7 @@ def callcatch(ui, func):
         elif not msg:
             ui.warn(_(" empty string\n"))
         else:
-            ui.warn("\n%r\n" % stringutil.ellipsis(msg))
+            ui.warn("\n%r\n" % pycompat.bytestr(stringutil.ellipsis(msg)))
     except error.CensoredNodeError as inst:
         ui.warn(_("abort: file censored %s!\n") % inst)
     except error.RevlogError as inst: