Hi Elijah,
On Tue, 30 Mar 2021, Elijah Newren via GitGitGadget wrote:
> From: Elijah Newren <newren@xxxxxxxxx>
>
> save_opts() should save any non-default values. It was intended to do
> this, but since most options in struct replay_opts default to 0, it only
> saved non-zero values. Unfortunately, this does not always work for
> options.edit. Roughly speaking, options.edit had a default value of 0
> for cherry-pick but a default value of 1 for revert. Make save_opts()
> record a value whenever it differs from the default.
>
> options.edit was also overly simplistic; we had more than two cases.
> The behavior that previously existed was as follows:
>
> Non-conflict commits Right after Conflict
> revert Edit iff isatty(0) Edit (ignore isatty(0))
> cherry-pick No edit See above
> Specify --edit Edit (ignore isatty(0)) See above
> Specify --no-edit (*) See above
>
> (*) Before stopping for conflicts, No edit is the behavior. After
> stopping for conflicts, the --no-edit flag is not saved so see
> the first two rows.
>
> However, the expected behavior is:
>
> Non-conflict commits Right after Conflict
> revert Edit iff isatty(0) Edit iff isatty(0)
> cherry-pick No edit Edit iff isatty(0)
> Specify --edit Edit (ignore isatty(0)) Edit (ignore isatty(0))
> Specify --no-edit No edit No edit
>
> In order to get the expected behavior, we need to change options.edit
> to a tri-state: unspecified, false, or true. When specified, we follow
> what it says. When unspecified, we need to check whether the current
> commit being created is resolving a conflict as well as consulting
> options.action and isatty(0). While at it, add a should_edit() utility
> function that compresses options.edit down to a boolean based on the
> additional information for the non-conflict case.
>
> continue_single_pick() is the function responsible for resuming after
> conflict cases, regardless of whether there is one commit being picked
> or many. Make this function stop assuming edit behavior in all cases,
> so that it can correctly handle !isatty(0) and specific requests to not
> edit the commit message.
Nicely explained!
I'll allow myself one tangent: the subject of the sequencer's Unix shell
script heritage seems to come up with an increasing frequency, in
particular the awful "let's write out one file per setting" strategy.
I would _love_ for `save_opts()` to write a JSON instead (or an INI via
the `git_config_*()` family of functions, as is done already by the
cherry-pick/revert stuff), now that we no longer have any shell script
backend (apart from `--preserve-merges`, but that one is on its way out
anyway).
The one thing that concerns me with this idea is that I know for a fact
that some enterprisey users play games with those files inside
`<GIT_DIR>/rebase-merge` that should be considered internal implementation
details. Not sure how to deprecate that properly, I don't think we have a
sane way to detect whether users rely on these implementation details
other than breaking their expectations, which is not really a gentle way
to ask them to update their scripts.
> diff --git a/builtin/revert.c b/builtin/revert.c
> index 314a86c5621b..81441020231a 100644
> --- a/builtin/revert.c
> +++ b/builtin/revert.c
> @@ -182,7 +182,7 @@ static int run_sequencer(int argc, const char **argv, struct replay_opts *opts)
> "--signoff", opts->signoff,
> "--no-commit", opts->no_commit,
> "-x", opts->record_origin,
> - "--edit", opts->edit,
> + "--edit", opts->edit == 1,
Honestly, I'd prefer `> 0` here.
> NULL);
>
> if (cmd) {
> @@ -230,8 +230,6 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
> struct replay_opts opts = REPLAY_OPTS_INIT;
> int res;
>
> - if (isatty(0))
> - opts.edit = 1;
> opts.action = REPLAY_REVERT;
> sequencer_init_config(&opts);
> res = run_sequencer(argc, argv, &opts);
> diff --git a/sequencer.c b/sequencer.c
> index 848204d3dc3f..d444c778a097 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -1860,14 +1860,26 @@ static void record_in_rewritten(struct object_id *oid,
> flush_rewritten_pending();
> }
>
> +static int should_edit(struct replay_opts *opts) {
> + assert(opts->edit >= -1 && opts->edit <= 1);
Do we really want to introduce more of these useless `assert()`s? I know
that we stopped converting them to `BUG()`, but I really dislike
introducing new ones: they have very little effect, being no-ops by
default in most setups.
> + if (opts->edit == -1)
Maybe `< 0`, as we do elsewhere for "not specified"?
> + /*
> + * Note that we only handle the case of non-conflicted
> + * commits; continue_single_pick() handles the conflicted
> + * commits itself instead of calling this function.
> + */
> + return (opts->action == REPLAY_REVERT && isatty(0)) ? 1 : 0;
Apart from the extra parentheses, that makes sense to me.
> + return opts->edit;
> +}
> +
> static int do_pick_commit(struct repository *r,
> enum todo_command command,
> struct commit *commit,
> struct replay_opts *opts,
> int final_fixup, int *check_todo)
> {
> - unsigned int flags = opts->edit ? EDIT_MSG : 0;
> - const char *msg_file = opts->edit ? NULL : git_path_merge_msg(r);
> + unsigned int flags = should_edit(opts) ? EDIT_MSG : 0;
> + const char *msg_file = should_edit(opts) ? NULL : git_path_merge_msg(r);
> struct object_id head;
> struct commit *base, *next, *parent;
> const char *base_label, *next_label;
> @@ -3101,9 +3113,9 @@ static int save_opts(struct replay_opts *opts)
> if (opts->no_commit)
> res |= git_config_set_in_file_gently(opts_file,
> "options.no-commit", "true");
> - if (opts->edit)
> - res |= git_config_set_in_file_gently(opts_file,
> - "options.edit", "true");
> + if (opts->edit != -1)
s/!= -1/>= 0/
> + res |= git_config_set_in_file_gently(opts_file, "options.edit",
> + opts->edit ? "true" : "false");
> if (opts->allow_empty)
> res |= git_config_set_in_file_gently(opts_file,
> "options.allow-empty", "true");
> @@ -4077,7 +4089,7 @@ static int pick_commits(struct repository *r,
> prev_reflog_action = xstrdup(getenv(GIT_REFLOG_ACTION));
> if (opts->allow_ff)
> assert(!(opts->signoff || opts->no_commit ||
> - opts->record_origin || opts->edit ||
> + opts->record_origin || should_edit(opts) ||
> opts->committer_date_is_author_date ||
> opts->ignore_date));
> if (read_and_refresh_cache(r, opts))
> @@ -4370,14 +4382,35 @@ static int pick_commits(struct repository *r,
> return sequencer_remove_state(opts);
> }
>
> -static int continue_single_pick(struct repository *r)
> +static int continue_single_pick(struct repository *r, struct replay_opts *opts)
> {
> - const char *argv[] = { "commit", NULL };
> + struct strvec argv = STRVEC_INIT;
> + int want_edit;
Do we really want that extra `want_edit` variable? I think the code would
be easier to read without it, and still be obvious enough.
> + 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"));
> - return run_command_v_opt(argv, RUN_GIT_CMD);
> +
> + 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.
> + */
> + want_edit = (opts->edit == 1) || ((opts->edit == -1) && isatty(0));
> + if (!want_edit)
Here is what I would prefer:
if (!opts->edit || (opts->edit < 0 && !isatty(0)))
The rest looks good, and the comments are _really_ helpful.
And the remainder of the patch also looks good, so I will spare readers
time by not even quoting it.
Thank you!
Dscho
