[BUG] --pretty=format does not work ok with rev-list

Hello list, my name is Renzo Carbonara and I'm new here in the git neighborhood.

Now back to business, when using --pretty=format:some_format with git rev-list, an additional non-requested line is printed before every commit ("commit <sha1_id>"). Example:

git rev-list output (BAD):

k@k0001 ~/linux-2.6 $ git rev-list -2 --pretty=format:"%H: %cn" master commit f4be31ec9690cfe6e94fcbed6ae60a6a38b3c3ed f4be31ec9690cfe6e94fcbed6ae60a6a38b3c3ed: Linus Torvalds commit 44cad261025c04327fd7e847a7088fd3031b0c3e 44cad261025c04327fd7e847a7088fd3031b0c3e: Linus Torvalds

git log output (GOOD):

k@k0001 ~/linux-2.6 $ git log -2 --pretty=format:"%H: %cn" master f4be31ec9690cfe6e94fcbed6ae60a6a38b3c3ed: Linus Torvalds 44cad261025c04327fd7e847a7088fd3031b0c3e: Linus Torvalds

this was tested with versions:
 - 1.5.3.7
 - 4cdda2b895dfb6ba084e3952cbf4274a6a2e0338

Cheers,

Renzo Carbonara