[PATCH 00/15] submodule-config cleanup

The aim of this series is to cleanup the submodule-config and make it simpler
to use.  The two main parts to this series are:
(1) removing the ability to overlay the repository's config over the
    submodule-config.  This makes the API clunky as you don't really know when
    you want to overlay and when you don't.  So instead all the relevant
    sections (where you are interested in the repository's config) are patched
    to read the configuration directly from the repository's config.
(2) Add the ability to lazy-load the gitmodules file from the working
    directory.  Most callers are required to first populate the
    submodule-config by calling gitmodules_config.  Instead let's just
    lazy-load it if needed.  Only a couple callers will still require loading
    the gitmodules files by hand while the rest can have it lazy-loaded and no
    longer need to explicitly load it themselves.  This falls more in line with
    how specific revisions are already lazy-loaded.

As a side note, instead of having unpack-trees read configuration for the 'update' config (which is used by submodule update) we may just want to drop respecting this all together as it doesn't make much sense in the context of a checkout or reset. If that's the case then we can make the parts of the code which use 'update' even simpler.

This series is built on and requires the 'bw/grep-recurse-submodules' and 'bc/object-id' branches.

Brandon Williams (15):
  t7411: check configuration parsing errors
  submodule: don't use submodule_from_name
  add, reset: ensure submodules can be added or reset
  submodule--helper: don't overlay config in remote_submodule_branch
  submodule--helper: don't overlay config in update-clone
  fetch: don't overlay config with submodule-config
  submodule: don't rely on overlayed config when setting diffopts
  unpack-trees: don't rely on overlayed config
  submodule: remove submodule_config callback routine
  diff: stop allowing diff to have submodules configured in .git/config
  submodule-config: remove support for overlaying repository config
  submodule-config: move submodule-config functions to
    submodule-config.c
  submodule-config: lazy-load a repository's .gitmodules file
  unpack-trees: improve loading of .gitmodules
  submodule: remove gitmodules_config

 builtin/add.c                    |   1 +
 builtin/checkout.c               |   3 +-
 builtin/commit.c                 |   1 -
 builtin/diff-files.c             |   1 -
 builtin/diff-index.c             |   1 -
 builtin/diff-tree.c              |   1 -
 builtin/diff.c                   |   2 -
 builtin/fetch.c                  |   5 --
 builtin/grep.c                   |   4 --
 builtin/ls-files.c               |   6 +-
 builtin/mv.c                     |   1 -
 builtin/read-tree.c              |   2 -
 builtin/reset.c                  |   3 +-
 builtin/rm.c                     |   1 -
 builtin/submodule--helper.c      |  42 ++++++------
 diff.c                           |   3 -
 submodule-config.c               |  65 ++++++++++++++----
 submodule-config.h               |   8 +--
 submodule.c                      | 140 ++++++++++++++++-----------------------
 submodule.h                      |   8 +--
 t/helper/test-submodule-config.c |   7 --
 t/t4027-diff-submodule.sh        |  67 -------------------
 t/t7400-submodule-basic.sh       |  10 ---
 t/t7411-submodule-config.sh      |  87 +++++-------------------
 unpack-trees.c                   |  54 +++++++++------
 25 files changed, 189 insertions(+), 334 deletions(-)