tests/test-ui-verbosity.py

util.system: avoid buffering of subprocess output when it is piped

util.system() copies subprocess' output through pipe if output file is not
stdout.  Because a file iterator has internal buffering, output won't be
flushed until enough data is available.  Therefore, it could easily miss
important messages such as "waiting for lock".

import os
from mercurial import ui

hgrc = os.environ['HGRCPATH']
f = open(hgrc)
basehgrc = f.read()
f.close()

print '      hgrc settings    command line options      final result   '
print '    quiet verbo debug   quiet verbo debug      quiet verbo debug'

for i in xrange(64):
    hgrc_quiet   = bool(i & 1<<0)
    hgrc_verbose = bool(i & 1<<1)
    hgrc_debug   = bool(i & 1<<2)
    cmd_quiet    = bool(i & 1<<3)
    cmd_verbose  = bool(i & 1<<4)
    cmd_debug    = bool(i & 1<<5)

    f = open(hgrc, 'w')
    f.write(basehgrc)
    f.write('\n[ui]\n')
    if hgrc_quiet:
        f.write('quiet = True\n')
    if hgrc_verbose:
        f.write('verbose = True\n')
    if hgrc_debug:
        f.write('debug = True\n')
    f.close()

    u = ui.ui()
    if cmd_quiet or cmd_debug or cmd_verbose:
        u.setconfig('ui', 'quiet', str(bool(cmd_quiet)))
        u.setconfig('ui', 'verbose', str(bool(cmd_verbose)))
        u.setconfig('ui', 'debug', str(bool(cmd_debug)))

    check = ''
    if u.debugflag:
        if not u.verbose or u.quiet:
            check = ' *'
    elif u.verbose and u.quiet:
        check = ' +'

    print ('%2d  %5s %5s %5s   %5s %5s %5s  ->  %5s %5s %5s%s'
           % (i, hgrc_quiet, hgrc_verbose, hgrc_debug,
              cmd_quiet, cmd_verbose, cmd_debug,
              u.quiet, u.verbose, u.debugflag, check))