# HG changeset patch
# User Martin von Zweigbergk <martinvonz@google.com>
# Date 1576175169 28800
# Node ID 66af68d4c7512e27be09372bbfd229e2307fe005
# Parent  cf065c6a0197de1728bb5e3fa5044d2821f07b87
pycompat: allow pycompat.sysbytes() even if input already is bytes

pycompat.sysstr() on py3 accepts an input that's already str
(i.e. unicode). This patch makes it so pycompat.sysbytes() on py3
accepts an input that's already bytes. Allowing that makes it possible
to do pycompat.sysbytes(fp.name) where fp.name is either bytes or
unicode, as we'll get when fp can come from either open() or
resources.open_binary().

Differential Revision: https://phab.mercurial-scm.org/D7621

diff -r cf065c6a0197 -r 66af68d4c751 mercurial/pycompat.py
--- a/mercurial/pycompat.py	Fri Dec 13 10:10:40 2019 -0800
+++ b/mercurial/pycompat.py	Thu Dec 12 10:26:09 2019 -0800
@@ -253,6 +253,8 @@
         This never raises UnicodeEncodeError, but only ASCII characters
         can be round-trip by sysstr(sysbytes(s)).
         """
+        if isinstance(s, bytes):
+            return s
         return s.encode('utf-8')
 
     def sysstr(s):