tests/test-profile.t

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".

test --time

  $ hg --time help -q help 2>&1 | grep time > /dev/null
  $ hg init a
  $ cd a

#if lsprof

test --profile

  $ hg --profile st 2>../out
  $ grep CallCount ../out > /dev/null || cat ../out

  $ hg --profile --config profiling.output=../out st
  $ grep CallCount ../out > /dev/null || cat ../out

  $ hg --profile --config profiling.format=text st 2>../out
  $ grep CallCount ../out > /dev/null || cat ../out

  $ echo "[profiling]" >> $HGRCPATH
  $ echo "format=kcachegrind" >> $HGRCPATH

  $ hg --profile st 2>../out
  $ grep 'events: Ticks' ../out > /dev/null || cat ../out

  $ hg --profile --config profiling.output=../out st
  $ grep 'events: Ticks' ../out > /dev/null || cat ../out

#endif

  $ cd ..