[PATCH 0/3] avoid quadratic behavior in fetch-pack

Here are my patches to deal with Martin's pathological case, split out for easy reading. I took a few timings to show that the results of the 3rd patch are noticeable even with 50,000 unique refs (which is still a lot, but something that I could conceive of a busy repo accumulating over time).

  [1/3]: fetch-pack: avoid quadratic list insertion in mark_complete
  [2/3]: commit.c: make compare_commits_by_commit_date global
  [3/3]: fetch-pack: avoid quadratic behavior in rev_list_push

And here's the diffstat to prove it is really not scary. :)

 commit.c     |  2 +-
 commit.h     |  2 ++
 fetch-pack.c | 16 ++++++++--------
 3 files changed, 11 insertions(+), 9 deletions(-)

-Peff