wireproto: fix repr(frame) to not crash by unknown type id Follows up 5ef2da00e935.

py3: use s.startswith() instead of s[n] while parsing patches I know 'bytes[n] in bytes' magically works, but I'm tired of finding which one breaks the tests.

py3: do not try to byte-stringify None in cmdutil.tryimportone() It's a debug message, so just use '' instead.

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.