[PATCH v5 00/17] hook.[ch]: new library to run hooks + simple hook conversion

A trivial update to the v4 of the series to migrate hook execution to the new hook.c hook execution library. For a meaningful overall summary see v4's CL[1].

The only update here is to stop using the "env" member of "struct child_process" in favor of "env_array".

This is in preparation for a re-roll of another series[2] to remove "argv" (and soon in a re-roll, "env") from that API. Without this update the two would semantically conflict.

1. https://lore.kernel.org/git/cover-v4-00.17-00000000000-20211101T184938Z-avarab@gmail.com/
2. https://lore.kernel.org/git/cover-0.5-00000000000-20211122T153605Z-avarab@gmail.com/

Emily Shaffer (14):
  hook: add 'run' subcommand
  gc: use hook library for pre-auto-gc hook
  am: convert {pre,post}-applypatch to use hook.h
  rebase: convert pre-rebase to use hook.h
  am: convert applypatch-msg to use hook.h
  merge: convert post-merge to use hook.h
  hooks: convert non-worktree 'post-checkout' hook to hook library
  hooks: convert worktree 'post-checkout' hook to hook library
  send-email: use 'git hook run' for 'sendemail-validate'
  git-p4: use 'git hook' to run hooks
  commit: convert {pre-commit,prepare-commit-msg} hook to hook.h
  read-cache: convert post-index-change to use hook.h
  receive-pack: convert push-to-checkout hook to hook.h
  run-command: remove old run_hook_{le,ve}() hook API

Ævar Arnfjörð Bjarmason (3):
  hook API: add a run_hooks() wrapper
  hook API: add a run_hooks_l() wrapper
  git hook run: add an --ignore-missing flag

 .gitignore                 |   1 +
 Documentation/git-hook.txt |  45 +++++++++++++
 Documentation/githooks.txt |   4 ++
 Makefile                   |   1 +
 builtin.h                  |   1 +
 builtin/am.c               |   6 +-
 builtin/checkout.c         |   3 +-
 builtin/clone.c            |   3 +-
 builtin/gc.c               |   3 +-
 builtin/hook.c             |  84 +++++++++++++++++++++++
 builtin/merge.c            |   2 +-
 builtin/rebase.c           |   3 +-
 builtin/receive-pack.c     |   7 +-
 builtin/worktree.c         |  27 +++-----
 command-list.txt           |   1 +
 commit.c                   |  15 +++--
 git-p4.py                  |  70 ++-----------------
 git-send-email.perl        |  22 +++---
 git.c                      |   1 +
 hook.c                     | 131 ++++++++++++++++++++++++++++++++++++
 hook.h                     |  57 ++++++++++++++++
 read-cache.c               |   3 +-
 reset.c                    |   3 +-
 run-command.c              |  32 ---------
 run-command.h              |  17 -----
 t/t1800-hook.sh            | 134 +++++++++++++++++++++++++++++++++++++
 t/t9001-send-email.sh      |   4 +-
 27 files changed, 522 insertions(+), 158 deletions(-)
 create mode 100644 Documentation/git-hook.txt
 create mode 100644 builtin/hook.c
 create mode 100755 t/t1800-hook.sh

Range-diff against v4:
 1:  d97d6734961 !  1:  4ca52feebb8 hook: add 'run' subcommand
    @@ hook.c: int hook_exists(const char *name)
     +		return 0;
     +
     +	cp->no_stdin = 1;
    -+	cp->env = hook_cb->options->env.v;
    ++	strvec_pushv(&cp->env_array, hook_cb->options->env.v);
     +	cp->stdout_to_stderr = 1;
     +	cp->trace2_hook_name = hook_cb->hook_name;
     +
 2:  ca6464f7d5e =  2:  6275b97a306 hook API: add a run_hooks() wrapper
 3:  173860afca1 =  3:  b5b3051b2e5 gc: use hook library for pre-auto-gc hook
 4:  80a2171ddaf =  4:  c88eb5d4c25 am: convert {pre,post}-applypatch to use hook.h
 5:  74f459db287 =  5:  1d8f7b7e4c1 hook API: add a run_hooks_l() wrapper
 6:  1fd70c0e88a =  6:  d49a1444345 rebase: convert pre-rebase to use hook.h
 7:  ccba3ddf52e =  7:  191fdad0165 am: convert applypatch-msg to use hook.h
 8:  2c23e8645ec =  8:  119b92fbeae merge: convert post-merge to use hook.h
 9:  cb95c79093b =  9:  359ba416e84 hooks: convert non-worktree 'post-checkout' hook to hook library
10:  f330600fec8 ! 10:  b7599be95a7 hooks: convert worktree 'post-checkout' hook to hook library
    @@ builtin/worktree.c: static int add_worktree(const char *path, const char *refnam
     
      ## hook.c ##
     @@ hook.c: static int pick_next_hook(struct child_process *cp,
    - 	cp->env = hook_cb->options->env.v;
    + 	strvec_pushv(&cp->env_array, hook_cb->options->env.v);
      	cp->stdout_to_stderr = 1;
      	cp->trace2_hook_name = hook_cb->hook_name;
     +	cp->dir = hook_cb->options->dir;
11:  a0b6818c766 = 11:  f1c84d7f627 git hook run: add an --ignore-missing flag
12:  efa35971e9f = 12:  4e0f94d9102 send-email: use 'git hook run' for 'sendemail-validate'
13:  98e0e3330fb = 13:  e858f332a62 git-p4: use 'git hook' to run hooks
14:  79ea5a2a4f5 = 14:  9a5956cc028 commit: convert {pre-commit,prepare-commit-msg} hook to hook.h
15:  81612f94707 = 15:  6fd47c4c499 read-cache: convert post-index-change to use hook.h
16:  43ecd6697e0 = 16:  b201ea46f4b receive-pack: convert push-to-checkout hook to hook.h
17:  9ef574fa30c = 17:  281d17b04db run-command: remove old run_hook_{le,ve}() hook API