py3: use pycompat.strkwargs() Otherwise we get an error attempting to dispatch a command with arguments because we're passing a dict with bytes keys. Differential Revision: https://phab.mercurial-scm.org/D4732

py3: ensure _start_response() is called with system string This was preventing HTTP 500's from being sent in Python 3. Differential Revision: https://phab.mercurial-scm.org/D4730

py3: convert arguments, cwd and env to native strings when spawning subprocess This keeps Windows happy.

py3: apply byteskwargs to contrib/perf

py3: un-byteify strings around os.system() and os.devnull in contrib/perf

py3: work around the lack of sys.maxint in contrib/perf

py3: switch contrib/perf from xrange to pycompat.xrange

py3: handle sysstr conversion around get/set attr in contrib/perf

py3: proxy posixfile objects to re-add a useful 'name' attribute on Windows This file object is used in the vfs layer, so there are many errors like this: ... File "mercurial\localrepo.py", line 2569, in savecommitmessage return self.pathto(fp.name[len(self.root) + 1:]) TypeError: 'int' object is not subscriptable It looks like the 'name' value is actually the fileno() value, and the documentation says the name parameter to PyFile_FromFd() is ignored. [1] I tried just assigning the attribute after osutil.posixfile() returns, but that crashes saying that it's read-only. [1] https://docs.python.org/3.6/c-api/file.html

py3: don't use os.getcwdb() on Windows to avoid DeprecationWarnings See also ac32685011a3.