Hi Cameron and Taylor
On 03/08/2021 23:07, Taylor Blau wrote:
On Tue, Aug 03, 2021 at 04:33:09PM -0500, Cameron Steffen wrote:
Perhaps the issue then is that the pre-commit hook should not run for
`git revert --continue`? It does not run for `git revert`.
The general rule for cherry-pick, revert and rebase is that if the
commit message is edited then the commit is made with --verify and if
the commit message is not being edited then the commit is made with
--no-verify. I think the reasoning for this is that if the user has
altered the commit message or contents and they have a pre-commit hook
set then it is reasonable to check the new commit is acceptable to the
hook. There are some exceptions to this which are oversights (for
example I think we always pass --no-verify when committing a conflict
resolution with 'git rebase --continue' even though the editor opens
when committing in that case - I should try and fix that)
For 'git revert --continue' the commit is made when sequencer_continue()
calls continue_single_pick() which looks like
static int continue_single_pick(struct repository *r, struct replay_opts
*opts)
{
struct strvec argv = STRVEC_INIT;
int ret;
if (!refs_ref_exists(get_main_ref_store(r), "CHERRY_PICK_HEAD") &&
!refs_ref_exists(get_main_ref_store(r), "REVERT_HEAD"))
return error(_("no cherry-pick or revert in progress"));
strvec_push(&argv, "commit");
/*
* continue_single_pick() handles the case of recovering from a
* conflict. should_edit() doesn't handle that case; for a conflict,
* we want to edit if the user asked for it, or if they didn't specify
* and stdin is a tty.
*/
if (!opts->edit || (opts->edit < 0 && !isatty(0)))
/*
* Include --cleanup=strip as well because we don't want the
* "# Conflicts:" messages.
*/
strvec_pushl(&argv, "--no-edit", "--cleanup=strip", NULL);
ret = run_command_v_opt(argv.v, RUN_GIT_CMD);
strvec_clear(&argv);
return ret;
}
It runs git commit directly and never passes --no-verify. I wouldn't be
opposed to someone adding support for --no-verify (and --no-edit) to
"cherry-pick/revert/rebase --continue" on the understanding that it only
applied when committing the conflict resolution. There is a possible
confusion for users though who might expect that the options passed with
'--continue' applied to all the commits made by the command.
This does look like an oversight to me, but you'll have to bear with me
since I am relatively unfamiliar with the sequencer code.
Ultimately `git revert` calls do_pick_commit()
This is what happens when we are picking commits, the commit made with
'--continue' uses a different code path
which either calls
do_commit() or run_git_commit(). A couple of curiosities there:
- do_commit() does fall back to run_git_commit() if it has the
VERIFY_MSG bit set in `flags`.
- run_git_commit() passes `-n` only when VERIFY_MSG *isn't* set, so
the VERIFY_MSG bit does imply that the pre-commit hook would be run
there.
- when do_pick_commit() does have to fall back to run_git_commit(), it
sets the VERIFY_MSG bit in flags.
Calling run_git_commit() there is not a fallback it, that call is used
to reword commits once they have been picked (see 450efe2d53 ("rebase
-i: always update HEAD before rewording", 2019-08-19) for the reasoning
behind this) . Because the message is being edited there is no point in
going through do_commit().
But we never end up calling run_git_commit() (except in the case of
errors) because do_pick_commit() special-cases `command == TODO_REVERT`
(which is the case for `git revert`) and calls `do_commit()`.
But it gets weirder: do_commit() calls run_git_commit() itself, but
before the caller in do_pick_commit() has had a chance to add VERIFY_MSG
to the flags.
do_commit() does not change the flags that it is called with - callers
that want VERIFY_MSG will set that before they call do_commit().
do_commit() is there to commit simple picks without forking 'git commit'
So I suspect that this is an oversight, but perhaps somebody more
familiar with this code could confirm my thinking.
I hope the above helps - basically the idea is "if the commit has been
edited use VERIFY_MSG" and --continue unhelpfully uses a completely
different code-path to the main commit picking/reverting loop.
Best Wishes
Phillip
Thanks,
Taylor
