rebase -i: support --committer-date-is-author-date

Rebase is implemented with two different backends - 'apply' and
'merge' each of which support a different set of options. In
particular the apply backend supports a number of options implemented
by 'git am' that are not implemented in the merge backend. This means
that the available options are different depending on which backend is
used which is confusing. This patch adds support for the
--committer-date-is-author-date option to the merge backend. This
option uses the author date of the commit that is being rewritten as
the committer date when the new commit is created.

Original-patch-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 83 insertions, 3 deletions

diff --git a/sequencer.c b/sequencer.c
index 968a2d4..78d09f9 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -149,6 +149,7 @@ static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete")
  * command-line.
  */
 static GIT_PATH_FUNC(rebase_path_gpg_sign_opt, "rebase-merge/gpg_sign_opt")
+static GIT_PATH_FUNC(rebase_path_cdate_is_adate, "rebase-merge/cdate_is_adate")
 static GIT_PATH_FUNC(rebase_path_orig_head, "rebase-merge/orig-head")
 static GIT_PATH_FUNC(rebase_path_verbose, "rebase-merge/verbose")
 static GIT_PATH_FUNC(rebase_path_quiet, "rebase-merge/quiet")
@@ -302,6 +303,8 @@ int sequencer_remove_state(struct replay_opts *opts)
 		}
 	}
 
+	free(opts->committer_name);
+	free(opts->committer_email);
 	free(opts->gpg_sign);
 	free(opts->strategy);
 	for (i = 0; i < opts->xopts_nr; i++)
@@ -872,6 +875,22 @@ static char *get_author(const char *message)
 	return NULL;
 }
 
+static const char *author_date_from_env_array(const struct argv_array *env)
+{
+	int i;
+	const char *date;
+
+	for (i = 0; i < env->argc; i++)
+		if (skip_prefix(env->argv[i],
+				"GIT_AUTHOR_DATE=", &date))
+			return date;
+	/*
+	 * If GIT_AUTHOR_DATE is missing we should have already errored out when
+	 * reading the script
+	 */
+	BUG("GIT_AUTHOR_DATE missing from author script");
+}
+
 static const char staged_changes_advice[] =
 N_("you have staged changes in your working tree\n"
 "If these changes are meant to be squashed into the previous commit, run:\n"
@@ -938,6 +957,10 @@ static int run_git_commit(struct repository *r,
 			     gpg_opt, gpg_opt);
 	}
 
+	if (opts->committer_date_is_author_date)
+		argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+				 author_date_from_env_array(&cmd.env_array));
+
 	argv_array_push(&cmd.args, "commit");
 
 	if (!(flags & VERIFY_MSG))
@@ -1315,6 +1338,7 @@ static int try_to_commit(struct repository *r,
 	struct strbuf err = STRBUF_INIT;
 	struct strbuf commit_msg = STRBUF_INIT;
 	char *amend_author = NULL;
+	const char *committer = NULL;
 	const char *hook_commit = NULL;
 	enum commit_msg_cleanup_mode cleanup;
 	int res = 0;
@@ -1406,10 +1430,32 @@ static int try_to_commit(struct repository *r,
 		goto out;
 	}
 
-	reset_ident_date();
+	if (opts->committer_date_is_author_date) {
+		struct ident_split id;
+		struct strbuf date = STRBUF_INIT;
+
+		if (split_ident_line(&id, author, (int)strlen(author)) < 0) {
+			res = error(_("invalid author identity '%s'"), author);
+			goto out;
+		}
+		if (!id.date_begin) {
+			res = error(_("corrupt author: missing date information"));
+			goto out;
+		}
+		strbuf_addf(&date, "@%.*s %.*s",
+			    (int)(id.date_end - id.date_begin), id.date_begin,
+			    (int)(id.tz_end - id.tz_begin), id.tz_begin);
+		committer = fmt_ident(opts->committer_name,
+				      opts->committer_email,
+				      WANT_COMMITTER_IDENT, date.buf,
+				      IDENT_STRICT);
+		strbuf_release(&date);
+	} else {
+		reset_ident_date();
+	}
 
 	if (commit_tree_extended(msg->buf, msg->len, &tree, parents, oid,
-				 author, NULL, opts->gpg_sign, extra)) {
+				 author, committer, opts->gpg_sign, extra)) {
 		res = error(_("failed to write commit object"));
 		goto out;
 	}
@@ -2532,6 +2578,11 @@ static int read_populate_opts(struct replay_opts *opts)
 			opts->signoff = 1;
 		}
 
+		if (file_exists(rebase_path_cdate_is_adate())) {
+			opts->allow_ff = 0;
+			opts->committer_date_is_author_date = 1;
+		}
+
 		if (file_exists(rebase_path_reschedule_failed_exec()))
 			opts->reschedule_failed_exec = 1;
 
@@ -2622,6 +2673,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 		write_file(rebase_path_drop_redundant_commits(), "%s", "");
 	if (opts->keep_redundant_commits)
 		write_file(rebase_path_keep_redundant_commits(), "%s", "");
+	if (opts->committer_date_is_author_date)
+		write_file(rebase_path_cdate_is_adate(), "%s", "");
 	if (opts->reschedule_failed_exec)
 		write_file(rebase_path_reschedule_failed_exec(), "%s", "");
 
@@ -3542,6 +3595,10 @@ static int do_merge(struct repository *r,
 			goto leave_merge;
 		}
 
+		if (opts->committer_date_is_author_date)
+			argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+					 author_date_from_env_array(&cmd.env_array));
+
 		cmd.git_cmd = 1;
 		argv_array_push(&cmd.args, "merge");
 		argv_array_push(&cmd.args, "-s");
@@ -3819,7 +3876,8 @@ static int pick_commits(struct repository *r,
 	setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
 	if (opts->allow_ff)
 		assert(!(opts->signoff || opts->no_commit ||
-				opts->record_origin || opts->edit));
+			 opts->record_origin || opts->edit ||
+			 opts->committer_date_is_author_date));
 	if (read_and_refresh_cache(r, opts))
 		return -1;
 
@@ -4258,6 +4316,22 @@ static int commit_staged_changes(struct repository *r,
 	return 0;
 }
 
+static int init_committer(struct replay_opts *opts)
+{
+	struct ident_split id;
+	const char *committer;
+
+	committer = git_committer_info(IDENT_STRICT);
+	if (split_ident_line(&id, committer, strlen(committer)) < 0)
+		return error(_("invalid committer '%s'"), committer);
+	opts->committer_name =
+		xmemdupz(id.name_begin, id.name_end - id.name_begin);
+	opts->committer_email =
+		xmemdupz(id.mail_begin, id.mail_end - id.mail_end);
+
+	return 0;
+}
+
 int sequencer_continue(struct repository *r, struct replay_opts *opts)
 {
 	struct todo_list todo_list = TODO_LIST_INIT;
@@ -4269,6 +4343,9 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
 	if (read_populate_opts(opts))
 		return -1;
 	if (is_rebase_i(opts)) {
+		if (opts->committer_date_is_author_date && init_committer(opts))
+			return -1;
+
 		if ((res = read_populate_todo(r, &todo_list, opts)))
 			goto release_todo_list;
 
@@ -5145,6 +5222,9 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 
 	res = -1;
 
+	if (opts->committer_date_is_author_date && init_committer(opts))
+		goto cleanup;
+
 	if (checkout_onto(r, opts, onto_name, &oid, orig_head))
 		goto cleanup;