Introduce a "repository" object to eventually make it easier to
work in multiple repositories (the primary focus is to work with
the superproject and its submodules) in a single process.

* bw/repo-object:
  ls-files: use repository object
  repository: enable initialization of submodules
  submodule: convert is_submodule_initialized to work on a repository
  submodule: add repo_read_gitmodules
  submodule-config: store the_submodule_cache in the_repository
  repository: add index_state to struct repo
  config: read config from a repository object
  path: add repo_worktree_path and strbuf_repo_worktree_path
  path: add repo_git_path and strbuf_repo_git_path
  path: worktree_git_path() should not use file relocation
  path: convert do_git_path to take a 'struct repository'
  path: convert strbuf_git_common_path to take a 'struct repository'
  path: always pass in commondir to update_common_dir
  path: create path.h
  environment: store worktree in the_repository
  environment: place key repository state in the_repository
  repository: introduce the repository object
  environment: remove namespace_len variable
  setup: add comment indicating a hack
  setup: don't perform lazy initialization of repository state

Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.

* bw/config-h:
  config: don't implicitly use gitdir or commondir
  config: respect commondir
  setup: teach discover_git_directory to respect the commondir
  config: don't include config.h by default
  config: remove git_config_iter
  config: create config.h

Convert 'is_submodule_initialized()' to take a repository object and
while we're at it, lets rename the function to 'is_submodule_active()'
and remove the NEEDSWORK comment.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Teach the repo object to be able to populate the submodule_cache by
reading the repository's gitmodules file.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* bw/ls-files-sans-the-index:
  ls-files: factor out tag calculation
  ls-files: factor out debug info into a function
  ls-files: convert show_files to take an index
  ls-files: convert show_ce_entry to take an index
  ls-files: convert prune_cache to take an index
  ls-files: convert ce_excluded to take an index
  ls-files: convert show_ru_info to take an index
  ls-files: convert show_other_files to take an index
  ls-files: convert show_killed_files to take an index
  ls-files: convert write_eolinfo to take an index
  ls-files: convert overlay_tree_on_cache to take an index
  tree: convert read_tree to take an index parameter
  convert: convert renormalize_buffer to take an index
  convert: convert convert_to_git to take an index
  convert: convert convert_to_git_filter_fd to take an index
  convert: convert crlf_to_git to take an index
  convert: convert get_cached_convert_stats_ascii to take an index

* bw/config-h:
  config: don't implicitly use gitdir or commondir
  config: respect commondir
  setup: teach discover_git_directory to respect the commondir
  config: don't include config.h by default
  config: remove git_config_iter
  config: create config.h
  alias: use the early config machinery to expand aliases
  t7006: demonstrate a problem with aliases in subdirectories
  t1308: relax the test verifying that empty alias values are disallowed
  help: use early config when autocorrecting aliases
  config: report correct line number upon error
  discover_git_directory(): avoid setting invalid git_dir

Stop including config.h by default in cache.h.  Instead only include
config.h in those files which require use of the config system.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Many commands learned to pay attention to submodule.recurse
configuration.

* sb/submodule-blanket-recursive:
  builtin/fetch.c: respect 'submodule.recurse' option
  builtin/push.c: respect 'submodule.recurse' option
  builtin/grep.c: respect 'submodule.recurse' option
  Introduce 'submodule.recurse' option for worktree manipulators
  submodule loading: separate code path for .gitmodules and config overlay
  reset/checkout/read-tree: unify config callback for submodule recursion
  submodule test invocation: only pass additional arguments
  submodule recursing: do not write a config variable twice

Any command that understands '--recurse-submodules' can have its
default changed to true, by setting the new 'submodule.recurse'
option.

This patch includes read-tree/checkout/reset for working tree
manipulating commands. Later patches will cover other commands.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

The .gitmodules file is not supposed to have all the options available,
that are available in the configuration so separate it out.

A configuration option such as the hypothetical submodule.color.diff
that determines in which color a submodule change is printed,
is a very user specific thing, that the .gitmodules file should
not tamper with.

The .gitmodules file should only be used for settings that required
to setup the project in which the .gitmodules file is tracked. As the
minimum this would only include the name<->path mapping of the
submodule and its URL and branch.

Any further setting (such as 'fetch.recursesubmodules' or
'submodule.<name>.{update, ignore, shallow}') is not specific
to the project setup requirements, but rather is a distribution
of suggested developer configurations.  In other areas of Git
a suggested developer configuration is not transported in-tree
but via other means.  In an organisation this could be done
by deploying an opinionated system wide config (/etc/gitconfig)
or by putting the settings in the users home directory when
they start at the organisation. In open source projects this
is often accomplished via extensive READMEs (cf. our
SubmittingPatches/CodingGuidlines).

As a later patch in this series wants to introduce
a generic submodule recursion option, we want to make
sure that switch is not exposed via the gitmodules file.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>