A broken access to object databases in recent update to "git grep
--recurse-submodules" has been fixed.

* bw/grep-recurse-submodules:
  grep: take the read-lock when adding a submodule

With --recurse-submodules, we add each submodule that we encounter to
the list of alternate object databases. With threading, our changes to
the list are not protected against races. Indeed, ThreadSanitizer
reports a race when we call `add_to_alternates_memory()` around the same
time that another thread is reading in the list through
`read_sha1_file()`.

Take the grep read-lock while adding the submodule. The lock is used to
serialize uses of non-thread-safe parts of Git's API, including
`read_sha1_file()`.

Helped-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Acked-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

This is the "theoretically more correct" approach of simply
stepping back to the state before plumbing commands started paying
attention to "color.ui" configuration variable.

Let's run with this one.

* jk/ref-filter-colors-fix:
  tag: respect color.ui config
  Revert "color: check color.ui in git_default_config()"
  Revert "t6006: drop "always" color config tests"
  Revert "color: make "always" the same as "auto" in config"

This reverts commit 136c8c8b8fa39f1315713248473dececf20f8fe7.

That commit was trying to address a bug caused by 4c7f1819b3
(make color.ui default to 'auto', 2013-06-10), in which
plumbing like diff-tree defaulted to "auto" color, but did
not respect a "color.ui" directive to disable it.

But it also meant that we started respecting "color.ui" set
to "always". This was a known problem, but 4c7f1819b3 argued
that nobody ought to be doing that. However, that turned out
to be wrong, and we got a number of bug reports related to
"add -p" regressing in v2.14.2.

Let's revert 136c8c8b8, fixing the regression to "add -p".
This leaves the problem from 4c7f1819b3 unfixed, but:

  1. It's a pretty obscure problem in the first place. I
     only noticed it while working on the color code, and we
     haven't got a single bug report or complaint about it.

  2. We can make a more moderate fix on top by respecting
     "never" but not "always" for plumbing commands. This
     is just the minimal fix to go back to the working state
     we had before v2.14.2.

Note that this isn't a pure revert. We now have a test in
t3701 which shows off the "add -p" regression. This can be
flipped to success.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Code clean-up to avoid mixing values read from the .gitmodules file
and values read from the .git/config file.

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

"%C(color name)" in the pretty print format always produced ANSI
color escape codes, which was an early design mistake.  They now
honor the configuration (e.g. "color.ui = never") and also tty-ness
of the output medium.

* jk/ref-filter-colors:
  ref-filter: consult want_color() before emitting colors
  pretty: respect color settings for %C placeholders
  rev-list: pass diffopt->use_colors through to pretty-print
  for-each-ref: load config earlier
  color: check color.ui in git_default_config()
  ref-filter: pass ref_format struct to atom parsers
  ref-filter: factor out the parsing of sorting atoms
  ref-filter: make parse_ref_filter_atom a private function
  ref-filter: provide a function for parsing sort options
  ref-filter: move need_color_reset_at_eol into ref_format
  ref-filter: abstract ref format into its own struct
  ref-filter: simplify automatic color reset
  t: use test_decode_color rather than literal ANSI codes
  docs/for-each-ref: update pointer to color syntax
  check return value of verify_ref_format()

"git grep --recurse-submodules" has been reworked to give a more
consistent output across submodule boundary (and do its thing
without having to fork a separate process).

* bw/grep-recurse-submodules:
  grep: recurse in-process using 'struct repository'
  submodule: merge repo_read_gitmodules and gitmodules_config
  submodule: check for unmerged .gitmodules outside of config parsing
  submodule: check for unstaged .gitmodules outside of config parsing
  submodule: remove fetch.recursesubmodules from submodule-config parsing
  submodule: remove submodule.fetchjobs from submodule-config parsing
  config: add config_from_gitmodules
  cache.h: add GITMODULES_FILE macro
  repository: have the_repository use the_index
  repo_read_index: don't discard the index

"%C(color name)" in the pretty print format always produced ANSI
color escape codes, which was an early design mistake.  They now
honor the configuration (e.g. "color.ui = never") and also tty-ness
of the output medium.

* jk/ref-filter-colors:
  ref-filter: consult want_color() before emitting colors
  pretty: respect color settings for %C placeholders
  rev-list: pass diffopt->use_colors through to pretty-print
  for-each-ref: load config earlier
  color: check color.ui in git_default_config()
  ref-filter: pass ref_format struct to atom parsers
  ref-filter: factor out the parsing of sorting atoms
  ref-filter: make parse_ref_filter_atom a private function
  ref-filter: provide a function for parsing sort options
  ref-filter: move need_color_reset_at_eol into ref_format
  ref-filter: abstract ref format into its own struct
  ref-filter: simplify automatic color reset
  t: use test_decode_color rather than literal ANSI codes
  docs/for-each-ref: update pointer to color syntax
  check return value of verify_ref_format()

Conversion from uchar[20] to struct object_id continues.

* bc/object-id:
  sha1_name: convert uses of 40 to GIT_SHA1_HEXSZ
  sha1_name: convert GET_SHA1* flags to GET_OID*
  sha1_name: convert get_sha1* to get_oid*
  Convert remaining callers of get_sha1 to get_oid.
  builtin/unpack-file: convert to struct object_id
  bisect: convert bisect_checkout to struct object_id
  builtin/update_ref: convert to struct object_id
  sequencer: convert to struct object_id
  remote: convert struct push_cas to struct object_id
  submodule: convert submodule config lookup to use object_id
  builtin/merge-tree: convert remaining caller of get_sha1 to object_id
  builtin/fsck: convert remaining caller of get_sha1 to object_id

Now that the submodule-config subsystem can lazily read the gitmodules
file we no longer need to explicitly pre-read the gitmodules by calling
'gitmodules_config()' so let's remove it.

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