[PATCH 00/14] Build in merge

Sorry for the resend, but I again squashed an unrelated hunk to the last
patch, so I'm sending the changed patches:

08: Add new test to ensure git-merge handles more than 25 refs.
13: git-commit-tree: make it usable from other builtins
14: Build in merge

I really hope I won't overlook this next time.

The interdiff from the previous version is empty, I just moved that
unrelated hunk from patch 13 to patch 08.

Junio C Hamano (2):
  Introduce get_merge_bases_many()
  Introduce reduce_heads()

Miklos Vajna (12):
  Move split_cmdline() to alias.c
  Move commit_list_count() to commit.c
  Move parse-options's skip_prefix() to git-compat-util.h
  Add new test to ensure git-merge handles pull.twohead and
    pull.octopus
  Move read_cache_unmerged() to read-cache.c
  git-fmt-merge-msg: make it usable from other builtins
  Introduce get_octopus_merge_bases() in commit.c
  Add new test to ensure git-merge handles more than 25 refs.
  Add new test case to ensure git-merge reduces octopus parents when
    possible
  Add new test case to ensure git-merge prepends the custom merge
    message
  git-commit-tree: make it usable from other builtins
  Build in merge

 Makefile                                      |    2 +-
 alias.c                                       |   54 ++
 builtin-commit-tree.c                         |   71 +-
 builtin-fmt-merge-msg.c                       |  155 ++--
 builtin-merge-recursive.c                     |    8 -
 builtin-merge.c                               | 1148 +++++++++++++++++++++++++
 builtin-read-tree.c                           |   24 -
 builtin-remote.c                              |   39 +-
 builtin.h                                     |    8 +
 cache.h                                       |    3 +
 commit.c                                      |  136 +++-
 commit.h                                      |    4 +
 git-merge.sh => contrib/examples/git-merge.sh |    0 
 git-compat-util.h                             |    6 +
 git.c                                         |   54 +--
 parse-options.c                               |    6 -
 read-cache.c                                  |   31 +
 t/t7601-merge-pull-config.sh                  |  129 +++
 t/t7602-merge-octopus-many.sh                 |   52 ++
 t/t7603-merge-reduce-heads.sh                 |   63 ++
 t/t7604-merge-custom-message.sh               |   37 +
 21 files changed, 1811 insertions(+), 219 deletions(-)
 create mode 100644 builtin-merge.c
 rename git-merge.sh => contrib/examples/git-merge.sh (100%)
 create mode 100755 t/t7601-merge-pull-config.sh
 create mode 100755 t/t7602-merge-octopus-many.sh
 create mode 100755 t/t7603-merge-reduce-heads.sh
 create mode 100755 t/t7604-merge-custom-message.sh