py3: work around weird handling of bytes/unicode in decode_header() Basically decode_header() works as follows, and on Python 3, email headers ARE UNICODE. def decode_header(header): if not ecre.search(header): # ecre is unicode regexp return [(header, None)] # so header is unicode string ... decode header into [(bytes_data, unicode_charset_name)] return collapsed

py3: use system string to access email headers

py3: fix string issues of email message in test-import.t - payload can be bytes - headers must be unicode on Python 3 - need to call msg.as_bytes() on Python 3, but msg.as_string() on Python 2, where bytes(msg) magic works

py3: use lower-cased module 'email.message' in test-import.t

py3: drop b'' from error message of fancyopts

procutil: drop unused 'newlines' option from popen*() (API) It's unlikely for us to use the universal_newlines option.

procutil: make explainexit() simply return a message (API) Almost all callers want it.

procutil: do not convert return code of signal exit to positive number (API) The docstring states that "codes from kill are negative", and it doesn't make sense to make exit/signal code ambiguous. .. api:: ``hook.hook()`` and ``hook.runhooks()`` may return a negative integer to denote that the process was killed by signal.

procutil: fix error message of tempfile filter First, we need to use procutil.system() to get an exit code compatible with explainexit(). Second, explainexit() returns (msg, code) tuple.

procutil: unify platform.explainexit() Since 4368f582c806 "use subprocess instead of os.system", posix.explainexit() is the superset of Windows implementation.