rebase -i: support --ignore-date

As part of the on-going effort to retire the apply rebase backend
teach the merge backend how to handle --ignore-date. We take care to
handle the combination of --ignore-date and
--committer-date-is-author-date in the same way as the apply backend.

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>

Documentation/git-rebase.txt

@@ -450,8 +450,9 @@ See also INCOMPATIBLE OPTIONS below.
 	date. This option implies --force-rebase.
 
 --ignore-date::
-	This flag is passed to 'git am' to change the author date
-	of each rebased commit (see linkgit:git-am[1]).
+	Instead of using the author date of the original commit, use
+	the current time as the	author date of the rebased commit.  This
+	option implies `--force-rebase`.
 +
 See also INCOMPATIBLE OPTIONS below.
 
@@ -589,7 +590,6 @@ INCOMPATIBLE OPTIONS
 The following options:
 
  * --apply
- * --ignore-date
  * --whitespace
  * -C
 
@@ -617,6 +617,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --empty=
  * --preserve-merges and --ignore-whitespace
  * --preserve-merges and --committer-date-is-author-date
+ * --preserve-merges and --ignore-date
  * --keep-base and --onto
  * --keep-base and --root
 

builtin/rebase.c

@@ -90,6 +90,7 @@ struct rebase_options {
 	char *gpg_sign_opt;
 	int autostash;
 	int committer_date_is_author_date;
+	int ignore_date;
 	char *cmd;
 	int allow_empty_message;
 	int rebase_merges, rebase_cousins;
@@ -129,6 +130,7 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 	replay.committer_date_is_author_date =
 					opts->committer_date_is_author_date;
+	replay.ignore_date = opts->ignore_date;
 	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 	replay.strategy = opts->strategy;
 
@@ -1008,6 +1010,8 @@ static int run_am(struct rebase_options *opts)
 		argv_array_push(&am.args, "--ignore-whitespace");
 	if (opts->committer_date_is_author_date)
 		argv_array_push(&opts->git_am_opts, "--committer-date-is-author-date");
+	if (opts->ignore_date)
+		argv_array_push(&opts->git_am_opts, "--ignore-date");
 	if (opts->action && !strcmp("continue", opts->action)) {
 		argv_array_push(&am.args, "--resolved");
 		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
@@ -1515,8 +1519,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "committer-date-is-author-date",
 			 &options.committer_date_is_author_date,
 			 N_("make committer date match author date")),
-		OPT_PASSTHRU_ARGV(0, "ignore-date", &options.git_am_opts, NULL,
-				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
+		OPT_BOOL(0, "ignore-date", &options.ignore_date,
+			 "ignore author date and use current date"),
 		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 				  N_("passed to 'git apply'"), 0),
 		OPT_BOOL(0, "ignore-whitespace", &options.ignore_whitespace,
@@ -1809,13 +1813,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	    options.autosquash) {
 		allow_preemptive_ff = 0;
 	}
-	if (options.committer_date_is_author_date)
+	if (options.committer_date_is_author_date || options.ignore_date)
 		options.flags |= REBASE_FORCE;
 
 	for (i = 0; i < options.git_am_opts.argc; i++) {
 		const char *option = options.git_am_opts.argv[i], *p;
-		if (!strcmp(option, "--ignore-date") ||
-		    !strcmp(option, "--whitespace=fix") ||
+		if (!strcmp(option, "--whitespace=fix") ||
 		    !strcmp(option, "--whitespace=strip"))
 			allow_preemptive_ff = 0;
 		else if (skip_prefix(option, "-C", &p)) {

sequencer.c

@@ -150,6 +150,7 @@ static GIT_PATH_FUNC(rebase_path_refs_to_delete, "rebase-merge/refs-to-delete")
  */
 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_ignore_date, "rebase-merge/ignore_date")
 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")
@@ -889,6 +890,24 @@ static const char *author_date_from_env_array(const struct argv_array *env)
 	BUG("GIT_AUTHOR_DATE missing from author script");
 }
 
+/* Construct a free()able author string with current time as the author date */
+static char *ignore_author_date(const char *author)
+{
+	int len = strlen(author);
+	struct ident_split ident;
+	struct strbuf new_author = STRBUF_INIT;
+
+	if (split_ident_line(&ident, author, len) < 0) {
+		error(_("malformed ident line '%s'"), author);
+		return NULL;
+	}
+
+	len = ident.mail_end - ident.name_begin + 1;
+	strbuf_addf(&new_author, "%.*s ", len, ident.name_begin);
+	datestamp(&new_author);
+	return strbuf_detach(&new_author, NULL);
+}
+
 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"
@@ -957,7 +976,11 @@ static int run_git_commit(struct repository *r,
 
 	if (opts->committer_date_is_author_date)
 		argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+				 opts->ignore_date ?
+				 "" :
 				 author_date_from_env_array(&cmd.env_array));
+	if (opts->ignore_date)
+		argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
 
 	argv_array_push(&cmd.args, "commit");
 
@@ -1387,7 +1410,8 @@ static int try_to_commit(struct repository *r,
 		strbuf_addf(&date, "@%.*s %.*s",
 			    (int)(ident.date_end - ident.date_begin), ident.date_begin,
 			    (int)(ident.tz_end - ident.tz_begin), ident.tz_begin);
-		res = setenv("GIT_COMMITTER_DATE", date.buf, 1);
+		res = setenv("GIT_COMMITTER_DATE",
+			     opts->ignore_date ? "" : date.buf, 1);
 		strbuf_release(&date);
 
 		if (res)
@@ -1453,6 +1477,16 @@ static int try_to_commit(struct repository *r,
 
 	reset_ident_date();
 
+	if (opts->ignore_date) {
+		author = ignore_author_date(author);
+		if (!author) {
+			res = -1;
+			goto out;
+		}
+		free(author_to_free);
+		author_to_free = (char *)author;
+	}
+
 	if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
 				 oid, author, opts->gpg_sign, extra)) {
 		res = error(_("failed to write commit object"));
@@ -2582,6 +2616,11 @@ static int read_populate_opts(struct replay_opts *opts)
 			opts->committer_date_is_author_date = 1;
 		}
 
+		if (file_exists(rebase_path_ignore_date())) {
+			opts->allow_ff = 0;
+			opts->ignore_date = 1;
+		}
+
 		if (file_exists(rebase_path_reschedule_failed_exec()))
 			opts->reschedule_failed_exec = 1;
 
@@ -2674,6 +2713,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 		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->ignore_date)
+		write_file(rebase_path_ignore_date(), "%s", "");
 	if (opts->reschedule_failed_exec)
 		write_file(rebase_path_reschedule_failed_exec(), "%s", "");
 
@@ -3596,7 +3637,11 @@ static int do_merge(struct repository *r,
 
 		if (opts->committer_date_is_author_date)
 			argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s",
+					 opts->ignore_date ?
+					 "" :
 					 author_date_from_env_array(&cmd.env_array));
+		if (opts->ignore_date)
+			argv_array_push(&cmd.env_array, "GIT_AUTHOR_DATE=");
 
 		cmd.git_cmd = 1;
 		argv_array_push(&cmd.args, "merge");
@@ -3876,7 +3921,8 @@ static int pick_commits(struct repository *r,
 	if (opts->allow_ff)
 		assert(!(opts->signoff || opts->no_commit ||
 				opts->record_origin || opts->edit ||
-				opts->committer_date_is_author_date));
+				opts->committer_date_is_author_date ||
+				opts->ignore_date));
 	if (read_and_refresh_cache(r, opts))
 		return -1;
 

sequencer.h

@@ -46,6 +46,7 @@ struct replay_opts {
 	int quiet;
 	int reschedule_failed_exec;
 	int committer_date_is_author_date;
+	int ignore_date;
 
 	int mainline;
 

t/t3436-rebase-more-options.sh

@@ -134,6 +134,63 @@ test_expect_success '--committer-date-is-author-date works when committing confl
 	test_cmp expect actual
 '
 
+# Checking for +0000 in author time is enough since default
+# timezone is UTC, but the timezone used while committing
+# sets to +0530.
+test_expect_success '--ignore-date works with apply backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --apply --ignore-date HEAD^ &&
+	git log -1 --pretty=%ai >authortime &&
+	grep "+0000" authortime
+'
+
+test_expect_success '--ignore-date works with merge backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --ignore-date -m HEAD^ &&
+	git log -1 --pretty=%ai >authortime &&
+	grep "+0000" authortime
+'
+
+test_expect_success '--ignore-date works after conflict resolution' '
+	test_must_fail git rebase --ignore-date -m \
+		--onto commit2^^ commit2^ commit2 &&
+	echo resolved >foo &&
+	git add foo &&
+	git rebase --continue &&
+	git log -1 --pretty=%ai >authortime &&
+	grep +0000 authortime
+'
+
+test_expect_success '--ignore-date works with rebase -r' '
+	git checkout side &&
+	git merge --no-ff commit3 &&
+	git rebase -r --root --ignore-date &&
+	git log --pretty=%ai >authortime &&
+	! grep -v "+0000" authortime
+'
+
+test_expect_success '--ignore-date with --committer-date-is-author-date works' '
+	test_must_fail git rebase -m --committer-date-is-author-date \
+		--ignore-date --onto commit2^^ commit2^ commit3 &&
+	git checkout --theirs foo &&
+	git add foo &&
+	git rebase --continue &&
+	git log -2 --pretty=%ai >authortime &&
+	git log -2 --pretty=%ci >committertime &&
+	test_cmp authortime committertime &&
+	! grep -v "+0000" authortime
+'
+
+test_expect_success '--ignore-date --committer-date-is-author-date works when forking merge' '
+	GIT_SEQUENCE_EDITOR="echo \"merge -C $(git rev-parse HEAD) commit3\">" \
+		git rebase -i --strategy=resolve --ignore-date \
+		--committer-date-is-author-date side side &&
+	git log -1 --pretty=%ai >authortime &&
+	git log -1 --pretty=%ci >committertime &&
+	test_cmp authortime committertime &&
+	grep "+0000" authortime
+ '
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged