Re: [PATCH v3 1/9] rebase -i: generate the script via rebase--helper

[Junio C Hamano <gitster@pobox.com>]

Johannes Schindelin <johannes.schindelin@gmx.de> writes:

> diff --git a/sequencer.c b/sequencer.c
> index 77afecaebf0..e858a976279 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -2388,3 +2388,48 @@ void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
>  
>  	strbuf_release(&sob);
>  }
> +
> +int sequencer_make_script(int keep_empty, FILE *out,
> +		int argc, const char **argv)
> +{
> +	char *format = xstrdup("%s");
> +	struct pretty_print_context pp = {0};
> +	struct strbuf buf = STRBUF_INIT;
> +	struct rev_info revs;
> +	struct commit *commit;
> +
> +	init_revisions(&revs, NULL);
> +	revs.verbose_header = 1;
> +	revs.max_parents = 1;
> +	revs.cherry_pick = 1;
> +	revs.limited = 1;
> +	revs.reverse = 1;
> +	revs.right_only = 1;
> +	revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
> +	revs.topo_order = 1;
> +
> +	revs.pretty_given = 1;
> +	git_config_get_string("rebase.instructionFormat", &format);
> +	get_commit_format(format, &revs);
> +	free(format);
> +	pp.fmt = revs.commit_format;
> +	pp.output_encoding = get_log_output_encoding();

All of the above feels like inviting unnecessary future breakages by
knowing too much about the implementation the current version of
revision.c happens to use.  A more careful implementation would be
to allocate our own av[] and prepare "--reverse", "--left-right",
"--cherry-pick", etc. to be parsed by setup_revisions() call we see
below.  The parsing is not an expensive part of the operation
anyway, and that way we do not have to worry about one less thing.

> +	if (setup_revisions(argc, argv, &revs, NULL) > 1)
> +		return error(_("make_script: unhandled options"));
> +
> +	if (prepare_revision_walk(&revs) < 0)
> +		return error(_("make_script: error preparing revisions"));
> +
> +	while ((commit = get_revision(&revs))) {
> +		strbuf_reset(&buf);
> +		if (!keep_empty && is_original_commit_empty(commit))
> +			strbuf_addf(&buf, "%c ", comment_line_char);

Presumably callers of this function (which does not exist yet at
this step) are expected to have done the configuration dance to
prepare comment_line_char to whatever the end-user specified?

> +		strbuf_addf(&buf, "pick %s ", oid_to_hex(&commit->object.oid));
> +		pretty_print_commit(&pp, commit, &buf);
> +		strbuf_addch(&buf, '\n');
> +		fputs(buf.buf, out);
> +	}
> +	strbuf_release(&buf);
> +	return 0;
> +}

Other than that, this looks reasonable.

> diff --git a/sequencer.h b/sequencer.h
> index f885b68395f..83f2943b7a9 100644
> --- a/sequencer.h
> +++ b/sequencer.h
> @@ -45,6 +45,9 @@ int sequencer_continue(struct replay_opts *opts);
>  int sequencer_rollback(struct replay_opts *opts);
>  int sequencer_remove_state(struct replay_opts *opts);
>  
> +int sequencer_make_script(int keep_empty, FILE *out,
> +		int argc, const char **argv);
> +
>  extern const char sign_off_header[];
>  
>  void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag);