win32mbcs: wrap underlying pycompat.bytestr to use checkwinfilename safely win32mbcs wraps some functions, to prevent them from unintentionally treating backslash (0x5c), which is used as the second or later byte of multi bytes characters by problematic encodings, as a path component delimiter on Windows platform. This wrapping assumes that wrapped functions can safely accept unicode string arguments. Unfortunately, d1937bdcee8c broke this assumption by introducing pycompat.bytestr() into util.checkwinfilename() for py3 support. After that, wrapped checkwinfilename() always fails for non-ASCII filename at pycompat.bytestr() invocation. This patch wraps underlying pycompat.bytestr() function to use util.checkwinfilename() safely. To avoid similar regression in the future, another patch series will add smoke testing on default branch.

--- a/hgext/win32mbcs.py	Tue May 09 15:08:47 2017 +0200
+++ b/hgext/win32mbcs.py	Fri May 12 21:46:14 2017 +0900
@@ -155,7 +155,8 @@
 # These functions are required to be called with local encoded string
 # because they expects argument is local encoded string and cause
 # problem with unicode string.
-rfuncs = '''mercurial.encoding.upper mercurial.encoding.lower'''
+rfuncs = '''mercurial.encoding.upper mercurial.encoding.lower
+ mercurial.pycompat.bytestr'''
 
 # List of Windows specific functions to be wrapped.
 winfuncs = '''os.path.splitunc'''