[PATCH v2 00/19] Make git-pull a builtin

This is a re-roll of [v1]. Thanks Johannes, Stefan and Junio for the reviews last round.

Previous versions:

[v1] http://thread.gmane.org/gmane.comp.version-control.git/269258

git-pull is a commonly executed command to check for new changes in the upstream repository and, if there are, fetch and integrate them into the current branch. Currently it is implemented by the shell script git-pull.sh. However, compared to C, shell scripts have certain deficiencies -- they need to spawn a lot of processes, introduce a lot of dependencies and cannot take advantage of git's internal caches.

This series rewrites git-pull.sh into a C builtin, thus improving its performance and portability. It is part of my GSoC project to rewrite git-pull and git-am into builtins[1].

[1] https://gist.github.com/pyokagan/1b7b0d1f4dab6ba3cef1

Paul Tan (19):
  parse-options-cb: implement parse_opt_pass_strbuf()
  parse-options-cb: implement parse_opt_pass_argv_array()
  argv-array: implement argv_array_pushv()
  pull: implement skeletal builtin pull
  pull: implement fetch + merge
  pull: pass verbosity, --progress flags to fetch and merge
  pull: pass git-merge's options to git-merge
  pull: pass git-fetch's options to git-fetch
  pull: error on no merge candidates
  pull: support pull.ff config
  pull: check if in unresolved merge state
  pull: fast-forward working tree if head is updated
  pull: implement pulling into an unborn branch
  pull: set reflog message
  pull: teach git pull about --rebase
  pull: configure --rebase via branch.<name>.rebase or pull.rebase
  pull --rebase: exit early when the working directory is dirty
  pull --rebase: error on no merge candidate cases
  pull: remove redirection to git-pull.sh

 Documentation/technical/api-argv-array.txt  |   3 +
 Makefile                                    |   2 +-
 advice.c                                    |   8 +
 advice.h                                    |   1 +
 argv-array.c                                |   6 +
 argv-array.h                                |   1 +
 builtin.h                                   |   1 +
 builtin/pull.c                              | 888 ++++++++++++++++++++++++++++
 git-pull.sh => contrib/examples/git-pull.sh |   0
 git.c                                       |   1 +
 parse-options-cb.c                          |  61 ++
 parse-options.h                             |   2 +
 12 files changed, 973 insertions(+), 1 deletion(-)
 create mode 100644 builtin/pull.c
 rename git-pull.sh => contrib/examples/git-pull.sh (100%)