git log: don't do merge diffs by default

git log: don't do merge diffs by default

I personally prefer "ignore_merges" to be on by default, because quite
often the merge diff is distracting and not interesting. That's true both
with "-p" and with "--stat" output.

If you want output from merges, you can trivially use the "-m", "-c" or
"--cc" flags to tell that you're interested in merges, which also tells
the diff generator what kind of diff to do (for --stat, any of the three
will do, of course, but they differ for plain patches or for
--patch-with-stat).

This trivial patch just removes the two lines that tells "git log" not to
ignore merges. It will still show the commit log message, of course, due
to the "always_show_header" part.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>