[PATCH v3 00/13] submodule: convert parts of 'update' to C

Original series: https://lore.kernel.org/git/20220210092833.55360-1-chooglen@google.com (I've trimmed the cc list down to the 'most interested' parties)

Thanks for the input, Ævar :) This just fixes up a few small issues in the previous version.

= Patch summary

- Patch 1 adds extra tests to "git submodule update" to make sure we
  don't break anything
- Patch 2 removes dead code that used to be part of "git submodule
  update"
- Patch 3 prepares for later changes by introducing the C function that
  will hold most of the newly converted code
- Patch 4 moves run-update-procedure's --suboid option into C
- Patch 5 moves ensure-core-worktree into C
- Patches 6-8 move run-update-procedure's --remote option into C
- Patches 9-11 move "git submodule update"'s --init into C
- Patches 12-13 move "git submodule update"'s --filter option into C

= Changes

Since v2:
- Patch 6: Fix a stale commit message that said 'in the next patch'.
- Patch 9: Fix an overly long line (spotted by Ævar in an older iteration of
  ar/submodule-update)
- Patch 12: Test for usage using test_expect_code
- Patch 13: Add missing spaces to the usage string

Since v1:
- Fix compilation error due to bad rebase
- Remove accidentally included tests
- Fix a NEEDSWORK (it was a leftover from ar/submodule-update)

Atharva Raykar (3):
  submodule--helper: get remote names from any repository
  submodule--helper: refactor get_submodule_displaypath()
  submodule--helper: allow setting superprefix for init_submodule()

Glen Choo (8):
  submodule--helper: remove update-module-mode
  submodule--helper: reorganize code for sh to C conversion
  submodule--helper run-update-procedure: remove --suboid
  submodule--helper: remove ensure-core-worktree
  submodule--helper run-update-procedure: learn --remote
  submodule--helper update-clone: learn --init
  submodule update: add tests for --filter
  submodule--helper update-clone: check for --filter and --init

Ævar Arnfjörð Bjarmason (2):
  submodule tests: test for init and update failure output
  submodule--helper: don't use bitfield indirection for parse_options()

 builtin/submodule--helper.c    | 248 +++++++++++++++++++--------------
 git-submodule.sh               |  54 +------
 t/t7406-submodule-update.sh    |  26 +++-
 t/t7408-submodule-reference.sh |  14 +-
 4 files changed, 183 insertions(+), 159 deletions(-)

Range-diff against v2:
 1:  6138f4682c =  1:  6138f4682c submodule tests: test for init and update failure output
 2:  6c83c78819 =  2:  6c83c78819 submodule--helper: remove update-module-mode
 3:  9524986096 =  3:  9524986096 submodule--helper: reorganize code for sh to C conversion
 4:  f42f3de2b7 =  4:  f42f3de2b7 submodule--helper run-update-procedure: remove --suboid
 5:  b0a0cae633 =  5:  b0a0cae633 submodule--helper: remove ensure-core-worktree
 6:  3bde7ccd61 !  6:  8dc7bc5894 submodule--helper: get remote names from any repository
    @@ Commit message
         submodule, all within the same process.
     
         We can now use this function to save an unnecessary subprocess spawn in
    -    `sync_submodule()`, and also in the next patch, which will require this
    -    functionality.
    +    `sync_submodule()`, and also in a subsequent patch, which will require
    +    this functionality.
     
         Mentored-by: Christian Couder <christian.couder@gmail.com>
         Mentored-by: Shourya Shukla <periperidip@gmail.com>
 7:  3b2caf7a35 =  7:  feaf9f45d8 submodule--helper: don't use bitfield indirection for parse_options()
 8:  81e9da8d42 =  8:  91e8e1a007 submodule--helper run-update-procedure: learn --remote
 9:  122da84ce4 !  9:  aba851e71e submodule--helper: refactor get_submodule_displaypath()
    @@ builtin/submodule--helper.c: static int resolve_relative_url_test(int argc, cons
      
     -/* the result should be freed by the caller. */
     -static char *get_submodule_displaypath(const char *path, const char *prefix)
    -+static char *do_get_submodule_displaypath(const char *path, const char *prefix, const char *super_prefix)
    ++static char *do_get_submodule_displaypath(const char *path,
    ++					  const char *prefix,
    ++					  const char *super_prefix)
      {
     -	const char *super_prefix = get_super_prefix();
     -
10:  fd52d6a2c3 = 10:  2155c049a2 submodule--helper: allow setting superprefix for init_submodule()
11:  9422c2ecac = 11:  03bbc39a06 submodule--helper update-clone: learn --init
12:  0a3e93998d ! 12:  e49b26ad94 submodule update: add tests for --filter
    @@ t/t7406-submodule-update.sh: test_expect_success 'submodule update --quiet passe
      '
      
     +test_expect_success 'submodule update --filter requires --init' '
    -+	test_must_fail git -C super submodule update --filter blob:none 2>err &&
    -+	grep "usage:" err
    ++	test_expect_code 129 git -C super submodule update --filter blob:none
     +'
     +
     +test_expect_success 'submodule update --filter sets partial clone settings' '
13:  6e1ef27191 ! 13:  c97c97948a submodule--helper update-clone: check for --filter and --init
    @@ builtin/submodule--helper.c: static int update_clone(int argc, const char **argv
      	const char *const git_submodule_helper_usage[] = {
     -		N_("git submodule--helper update-clone [--prefix=<path>] [<path>...]"),
     +		N_("git submodule [--quiet] update"
    -+		"[--init [--filter=<filter-spec>]] [--remote]"
    -+		"[-N|--no-fetch] [-f|--force]"
    -+		"[--checkout|--merge|--rebase]"
    -+		"[--[no-]recommend-shallow] [--reference <repository>]"
    -+		"[--recursive] [--[no-]single-branch] [--] [<path>...]"),
    ++		" [--init [--filter=<filter-spec>]] [--remote]"
    ++		" [-N|--no-fetch] [-f|--force]"
    ++		" [--checkout|--merge|--rebase]"
    ++		" [--[no-]recommend-shallow] [--reference <repository>]"
    ++		" [--recursive] [--[no-]single-branch] [--] [<path>...]"),
      		NULL
      	};
      	suc.prefix = prefix;

base-commit: 715d08a9e51251ad8290b181b6ac3b9e1f9719d7