windows: fix an issue causing registry config paths to be ignored on py3

`util.lookupreg()` returns bytes.

Differential Revision: https://phab.mercurial-scm.org/D7532

mercurial/scmwindows.py

@@ -1,65 +1,65 b''
 from __future__ import absolute_import
 
 import os
 
 from . import (
     encoding,
     pycompat,
     util,
     win32,
 )
 
 try:
     import _winreg as winreg
 
     winreg.CloseKey
 except ImportError:
     import winreg
 
 # MS-DOS 'more' is the only pager available by default on Windows.
 fallbackpager = b'more'
 
 
 def systemrcpath():
     '''return default os-specific hgrc search path'''
     rcpath = []
     filename = win32.executablepath()
     # Use mercurial.ini found in directory with hg.exe
     progrc = os.path.join(os.path.dirname(filename), b'mercurial.ini')
     rcpath.append(progrc)
     # Use hgrc.d found in directory with hg.exe
     progrcd = os.path.join(os.path.dirname(filename), b'hgrc.d')
     if os.path.isdir(progrcd):
         for f, kind in util.listdir(progrcd):
             if f.endswith(b'.rc'):
                 rcpath.append(os.path.join(progrcd, f))
     # else look for a system rcpath in the registry
     value = util.lookupreg(
         b'SOFTWARE\\Mercurial', None, winreg.HKEY_LOCAL_MACHINE
     )
-    if not isinstance(value, str) or not value:
+    if not isinstance(value, bytes) or not value:
         return rcpath
     value = util.localpath(value)
     for p in value.split(pycompat.ospathsep):
         if p.lower().endswith(b'mercurial.ini'):
             rcpath.append(p)
         elif os.path.isdir(p):
             for f, kind in util.listdir(p):
                 if f.endswith(b'.rc'):
                     rcpath.append(os.path.join(p, f))
     return rcpath
 
 
 def userrcpath():
     '''return os-specific hgrc search path to the user dir'''
     home = os.path.expanduser(b'~')
     path = [os.path.join(home, b'mercurial.ini'), os.path.join(home, b'.hgrc')]
     userprofile = encoding.environ.get(b'USERPROFILE')
     if userprofile and userprofile != home:
         path.append(os.path.join(userprofile, b'mercurial.ini'))
         path.append(os.path.join(userprofile, b'.hgrc'))
     return path
 
 
 def termsize(ui):
     return win32.termsize()