illumos gate

When running under python3, pbchk can produce a python stacktrace when spawning an external process such as cstyle.

Traceback (most recent call last):
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/git-pbchk", line 389, in <module>
    main(os.path.basename(sys.argv[0]), sys.argv[1:])
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/git-pbchk", line 381, in main
    pbchk(git_root(), parent_branch, None)
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/git-pbchk", line 348, in pbchk
    run_checks(root, parent, cmds)
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/git-pbchk", line 319, in run_checks
    output=s)
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/git-pbchk", line 266, in cstyle
    check_continuation=True)
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/../lib/python3.5/onbld/Checks/CStyle.py", line 55, in cstyle
    ret, tmpfile = processcheck('cstyle', options, fh, output)
  File "/build/illumos-omnios/usr/src/tools/proto/root_i386-nd/opt/onbld/bin/../lib/python3.5/onbld/Checks/ProcessCheck.py", line 63, in processcheck
    p.stdin.write(line)
TypeError: a bytes-like object is required, not 'str'

This is happening because git-pbchk is opening the file in non-binary mode (which in python 3 means as text with automatic character conversion from UTF-8 by default), but then attempting to feed this to a stdin pipe which needs bytes and not str.

The fix is for git-pbchk to open the file in binary mode when it is going to send the file handle over to be used on a pipe, which is the case for cstyle and manlint, and to make the backend processcheck function use a binary file handle to record the stdout.

However, since the manlint function in pbchk passes the same file handle to both manlint (which spawns an external perl process) and to spellcheck (which is internal in python), I have also modified spellcheck to do a binary->str conversion on lines read from the file handle which is in binary mode.