Comment by ramses0

In the case of `git log -100 | grep FOO`, the log output should go to stdout.

In the case of `git diff | grep FOO`, the diff output should go to stdout.

In the case of `git --help | grep FOO` the help output should go to stdout.

In the case of `git --omg-wtf | grep FOO`, it's fine if there is only output on stderr.