From ef484add9f6ba846c62e4f13ebe0ba99b9cc4aa5 Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Mon, 13 Jul 2020 11:10:41 +0100
Subject: [PATCH 1/6] rebase -i: add --ignore-whitespace flag

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
--ignore-whitespace option to the merge backend. This option treats
lines with only whitespace changes as unchanged and is implemented in
the merge backend by translating it to -Xignore-space-change.

Signed-off-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           | 19 +++++++-
 builtin/rebase.c                       | 19 ++++++--
 t/t3422-rebase-incompatible-options.sh |  1 -
 t/t3436-rebase-more-options.sh         | 60 ++++++++++++++++++++++++++
 4 files changed, 93 insertions(+), 6 deletions(-)
 create mode 100755 t/t3436-rebase-more-options.sh

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index f7a6033607..b003784f01 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -422,8 +422,23 @@ your branch contains commits which were dropped, this option can be used
 with `--keep-base` in order to drop those commits from your branch.
 
 --ignore-whitespace::
+	Ignore whitespace differences when trying to reconcile
+differences. Currently, each backend implements an approximation of
+this behavior:
++
+apply backend: When applying a patch, ignore changes in whitespace in
+context lines. Unfortunately, this means that if the "old" lines being
+replaced by the patch differ only in whitespace from the existing
+file, you will get a merge conflict instead of a successful patch
+application.
++
+merge backend: Treat lines with only whitespace changes as unchanged
+when merging. Unfortunately, this means that any patch hunks that were
+intended to modify whitespace and nothing else will be dropped, even
+if the other side had no changes that conflicted.
+
 --whitespace=<option>::
-	These flags are passed to the 'git apply' program
+	This flag is passed to the 'git apply' program
 	(see linkgit:git-apply[1]) that applies the patch.
 	Implies --apply.
 +
@@ -572,7 +587,6 @@ The following options:
  * --apply
  * --committer-date-is-author-date
  * --ignore-date
- * --ignore-whitespace
  * --whitespace
  * -C
 
@@ -598,6 +612,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
  * --preserve-merges and --empty=
+ * --preserve-merges and --ignore-whitespace
  * --keep-base and --onto
  * --keep-base and --root
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 27a07d4e78..bd93e9742c 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -126,6 +126,7 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
 	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 	replay.strategy = opts->strategy;
+
 	if (opts->strategy_opts)
 		parse_strategy_opts(&replay, opts->strategy_opts);
 
@@ -1466,6 +1467,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	struct strbuf revisions = STRBUF_INIT;
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id merge_base;
+	int ignore_whitespace = 0;
 	enum action action = ACTION_NONE;
 	const char *gpg_sign = NULL;
 	struct string_list exec = STRING_LIST_INIT_NODUP;
@@ -1495,9 +1497,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 		OPT_BOOL(0, "signoff", &options.signoff,
 			 N_("add a Signed-off-by: line to each commit")),
-		OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
-				  NULL, N_("passed to 'git am'"),
-				  PARSE_OPT_NOARG),
 		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
 				  &options.git_am_opts, NULL,
 				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
@@ -1505,6 +1504,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
 		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 				  N_("passed to 'git apply'"), 0),
+		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
+			 N_("ignore changes in whitespace")),
 		OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
 				  N_("action"), N_("passed to 'git apply'"), 0),
 		OPT_BIT('f', "force-rebase", &options.flags,
@@ -1850,6 +1851,18 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		imply_merge(&options, "--rebase-merges");
 	}
 
+	if (options.type == REBASE_APPLY) {
+		if (ignore_whitespace)
+			argv_array_push(&options.git_am_opts,
+					"--ignore-whitespace");
+	} else {
+		/* REBASE_MERGE and PRESERVE_MERGES */
+		if (ignore_whitespace) {
+			string_list_append(&strategy_options,
+					   "ignore-space-change");
+		}
+	}
+
 	if (strategy_options.nr) {
 		int i;
 
diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index 50e7960702..55ca46786d 100755
--- a/t/t3422-rebase-incompatible-options.sh
+++ b/t/t3422-rebase-incompatible-options.sh
@@ -61,7 +61,6 @@ test_rebase_am_only () {
 }
 
 test_rebase_am_only --whitespace=fix
-test_rebase_am_only --ignore-whitespace
 test_rebase_am_only --committer-date-is-author-date
 test_rebase_am_only -C4
 
diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
new file mode 100755
index 0000000000..4f8a6e51c9
--- /dev/null
+++ b/t/t3436-rebase-more-options.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+#
+# Copyright (c) 2019 Rohit Ashiwal
+#
+
+test_description='tests to ensure compatibility between am and interactive backends'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+# This is a special case in which both am and interactive backends
+# provide the same output. It was done intentionally because
+# both the backends fall short of optimal behaviour.
+test_expect_success 'setup' '
+	git checkout -b topic &&
+	test_write_lines "line 1" "	line 2" "line 3" >file &&
+	git add file &&
+	git commit -m "add file" &&
+
+	test_write_lines "line 1" "new line 2" "line 3" >file &&
+	git commit -am "update file" &&
+	git tag side &&
+
+	git checkout --orphan master &&
+	test_write_lines "line 1" "        line 2" "line 3" >file &&
+	git commit -am "add file" &&
+	git tag main
+'
+
+test_expect_success '--ignore-whitespace works with apply backend' '
+	test_must_fail git rebase --apply main side &&
+	git rebase --abort &&
+	git rebase --apply --ignore-whitespace main side &&
+	git diff --exit-code side
+'
+
+test_expect_success '--ignore-whitespace works with merge backend' '
+	test_must_fail git rebase --merge main side &&
+	git rebase --abort &&
+	git rebase --merge --ignore-whitespace main side &&
+	git diff --exit-code side
+'
+
+test_expect_success '--ignore-whitespace is remembered when continuing' '
+	(
+		set_fake_editor &&
+		FAKE_LINES="break 1" git rebase -i --ignore-whitespace \
+			main side &&
+		git rebase --continue
+	) &&
+	git diff --exit-code side
+'
+
+# This must be the last test in this file
+test_expect_success '$EDITOR and friends are unchanged' '
+	test_editor_unchanged
+'
+
+test_done

From e8cbe2118a8e3c1aa71ed8d93f96001decebde1d Mon Sep 17 00:00:00 2001
From: Phillip Wood <phillip.wood@dunelm.org.uk>
Date: Mon, 17 Aug 2020 18:40:01 +0100
Subject: [PATCH 2/6] am: stop exporting GIT_COMMITTER_DATE

The implementation of --committer-date-is-author-date exports
GIT_COMMITTER_DATE to override the default committer date but does not
reset GIT_COMMITTER_DATE in the environment after creating the commit
so it is set in the environment of any hooks that get run. We're about
to add the same functionality to the sequencer and do not want to have
GIT_COMMITTER_DATE set when running hooks or exec commands so lets
update commit_tree_extended() to take an explicit committer so we
override the default date without setting GIT_COMMITTER_DATE in the
environment.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/am.c     | 28 +++++++++++++++++++++++-----
 builtin/commit.c |  4 ++--
 commit.c         | 11 +++++++----
 commit.h         |  7 +++----
 ident.c          | 24 ++++++++++++++----------
 sequencer.c      |  4 ++--
 6 files changed, 51 insertions(+), 27 deletions(-)

diff --git a/builtin/am.c b/builtin/am.c
index e3dfd93c25..896cd0f827 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -98,6 +98,8 @@ struct am_state {
 	char *author_name;
 	char *author_email;
 	char *author_date;
+	char *committer_name;
+	char *committer_email;
 	char *msg;
 	size_t msg_len;
 
@@ -130,6 +132,8 @@ struct am_state {
  */
 static void am_state_init(struct am_state *state)
 {
+	const char *committer;
+	struct ident_split id;
 	int gpgsign;
 
 	memset(state, 0, sizeof(*state));
@@ -150,6 +154,14 @@ static void am_state_init(struct am_state *state)
 
 	if (!git_config_get_bool("commit.gpgsign", &gpgsign))
 		state->sign_commit = gpgsign ? "" : NULL;
+
+	committer = git_committer_info(IDENT_STRICT);
+	if (split_ident_line(&id, committer, strlen(committer)) < 0)
+		die(_("invalid committer: %s"), committer);
+	state->committer_name =
+		xmemdupz(id.name_begin, id.name_end - id.name_begin);
+	state->committer_email =
+		xmemdupz(id.mail_begin, id.mail_end - id.mail_end);
 }
 
 /**
@@ -161,6 +173,8 @@ static void am_state_release(struct am_state *state)
 	free(state->author_name);
 	free(state->author_email);
 	free(state->author_date);
+	free(state->committer_name);
+	free(state->committer_email);
 	free(state->msg);
 	argv_array_clear(&state->git_apply_opts);
 }
@@ -1556,7 +1570,7 @@ static void do_commit(const struct am_state *state)
 	struct object_id tree, parent, commit;
 	const struct object_id *old_oid;
 	struct commit_list *parents = NULL;
-	const char *reflog_msg, *author;
+	const char *reflog_msg, *author, *committer = NULL;
 	struct strbuf sb = STRBUF_INIT;
 
 	if (run_hook_le(NULL, "pre-applypatch", NULL))
@@ -1580,11 +1594,15 @@ static void do_commit(const struct am_state *state)
 			IDENT_STRICT);
 
 	if (state->committer_date_is_author_date)
-		setenv("GIT_COMMITTER_DATE",
-			state->ignore_date ? "" : state->author_date, 1);
+		committer = fmt_ident(state->committer_name,
+				      state->author_email, WANT_COMMITTER_IDENT,
+				      state->ignore_date ? NULL
+							 : state->author_date,
+				      IDENT_STRICT);
 
-	if (commit_tree(state->msg, state->msg_len, &tree, parents, &commit,
-			author, state->sign_commit))
+	if (commit_tree_extended(state->msg, state->msg_len, &tree, parents,
+				 &commit, author, committer, state->sign_commit,
+				 NULL))
 		die(_("failed to write commit object"));
 
 	reflog_msg = getenv("GIT_REFLOG_ACTION");
diff --git a/builtin/commit.c b/builtin/commit.c
index d3e7781e65..2785344fed 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1675,8 +1675,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	}
 
 	if (commit_tree_extended(sb.buf, sb.len, &active_cache_tree->oid,
-				 parents, &oid, author_ident.buf, sign_commit,
-				 extra)) {
+				 parents, &oid, author_ident.buf, NULL,
+				 sign_commit, extra)) {
 		rollback_index_files();
 		die(_("failed to write commit object"));
 	}
diff --git a/commit.c b/commit.c
index c7099daeac..fb63c22cc1 100644
--- a/commit.c
+++ b/commit.c
@@ -1324,8 +1324,8 @@ int commit_tree(const char *msg, size_t msg_len, const struct object_id *tree,
 	int result;
 
 	append_merge_tag_headers(parents, &tail);
-	result = commit_tree_extended(msg, msg_len, tree, parents, ret,
-				      author, sign_commit, extra);
+	result = commit_tree_extended(msg, msg_len, tree, parents, ret, author,
+				      NULL, sign_commit, extra);
 	free_commit_extra_headers(extra);
 	return result;
 }
@@ -1448,7 +1448,8 @@ N_("Warning: commit message did not conform to UTF-8.\n"
 int commit_tree_extended(const char *msg, size_t msg_len,
 			 const struct object_id *tree,
 			 struct commit_list *parents, struct object_id *ret,
-			 const char *author, const char *sign_commit,
+			 const char *author, const char *committer,
+			 const char *sign_commit,
 			 struct commit_extra_header *extra)
 {
 	int result;
@@ -1481,7 +1482,9 @@ int commit_tree_extended(const char *msg, size_t msg_len,
 	if (!author)
 		author = git_author_info(IDENT_STRICT);
 	strbuf_addf(&buffer, "author %s\n", author);
-	strbuf_addf(&buffer, "committer %s\n", git_committer_info(IDENT_STRICT));
+	if (!committer)
+		committer = git_committer_info(IDENT_STRICT);
+	strbuf_addf(&buffer, "committer %s\n", committer);
 	if (!encoding_is_utf8)
 		strbuf_addf(&buffer, "encoding %s\n", git_commit_encoding);
 
diff --git a/commit.h b/commit.h
index 008a0fa4a0..8f4227ae5c 100644
--- a/commit.h
+++ b/commit.h
@@ -316,10 +316,9 @@ int commit_tree(const char *msg, size_t msg_len,
 
 int commit_tree_extended(const char *msg, size_t msg_len,
 			 const struct object_id *tree,
-			 struct commit_list *parents,
-			 struct object_id *ret, const char *author,
-			 const char *sign_commit,
-			 struct commit_extra_header *);
+			 struct commit_list *parents, struct object_id *ret,
+			 const char *author, const char *committer,
+			 const char *sign_commit, struct commit_extra_header *);
 
 struct commit_extra_header *read_commit_extra_headers(struct commit *, const char **);
 
diff --git a/ident.c b/ident.c
index e666ee4e59..7cbf223350 100644
--- a/ident.c
+++ b/ident.c
@@ -361,11 +361,15 @@ N_("\n"
 const char *fmt_ident(const char *name, const char *email,
 		      enum want_ident whose_ident, const char *date_str, int flag)
 {
-	static struct strbuf ident = STRBUF_INIT;
+	static int index;
+	static struct strbuf ident_pool[2] = { STRBUF_INIT, STRBUF_INIT };
 	int strict = (flag & IDENT_STRICT);
 	int want_date = !(flag & IDENT_NO_DATE);
 	int want_name = !(flag & IDENT_NO_NAME);
 
+	struct strbuf *ident = &ident_pool[index];
+	index = (index + 1) % ARRAY_SIZE(ident_pool);
+
 	if (!email) {
 		if (whose_ident == WANT_AUTHOR_IDENT && git_author_email.len)
 			email = git_author_email.buf;
@@ -421,25 +425,25 @@ const char *fmt_ident(const char *name, const char *email,
 			die(_("name consists only of disallowed characters: %s"), name);
 	}
 
-	strbuf_reset(&ident);
+	strbuf_reset(ident);
 	if (want_name) {
-		strbuf_addstr_without_crud(&ident, name);
-		strbuf_addstr(&ident, " <");
+		strbuf_addstr_without_crud(ident, name);
+		strbuf_addstr(ident, " <");
 	}
-	strbuf_addstr_without_crud(&ident, email);
+	strbuf_addstr_without_crud(ident, email);
 	if (want_name)
-			strbuf_addch(&ident, '>');
+		strbuf_addch(ident, '>');
 	if (want_date) {
-		strbuf_addch(&ident, ' ');
+		strbuf_addch(ident, ' ');
 		if (date_str && date_str[0]) {
-			if (parse_date(date_str, &ident) < 0)
+			if (parse_date(date_str, ident) < 0)
 				die(_("invalid date format: %s"), date_str);
 		}
 		else
-			strbuf_addstr(&ident, ident_default_date());
+			strbuf_addstr(ident, ident_default_date());
 	}
 
-	return ident.buf;
+	return ident->buf;
 }
 
 const char *fmt_name(enum want_ident whose_ident)
diff --git a/sequencer.c b/sequencer.c
index 6fd2674632..968a2d4ef3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1408,8 +1408,8 @@ static int try_to_commit(struct repository *r,
 
 	reset_ident_date();
 
-	if (commit_tree_extended(msg->buf, msg->len, &tree, parents,
-				 oid, author, opts->gpg_sign, extra)) {
+	if (commit_tree_extended(msg->buf, msg->len, &tree, parents, oid,
+				 author, NULL, opts->gpg_sign, extra)) {
 		res = error(_("failed to write commit object"));
 		goto out;
 	}

From 7573cec52c0274ceb166c425be4288f6b3103d6f Mon Sep 17 00:00:00 2001
From: Phillip Wood <phillip.wood@dunelm.org.uk>
Date: Mon, 17 Aug 2020 18:40:02 +0100
Subject: [PATCH 3/6] 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>
---
 Documentation/git-rebase.txt           | 10 ++-
 builtin/rebase.c                       | 17 +++--
 sequencer.c                            | 86 +++++++++++++++++++++++++-
 sequencer.h                            |  3 +
 t/t3422-rebase-incompatible-options.sh |  1 -
 t/t3436-rebase-more-options.sh         | 58 ++++++++++++++++-
 6 files changed, 162 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index b003784f01..f9ddfe2e77 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -445,9 +445,13 @@ if the other side had no changes that conflicted.
 See also INCOMPATIBLE OPTIONS below.
 
 --committer-date-is-author-date::
+	Instead of using the current time as the committer date, use
+	the author date of the commit being rebased as the committer
+	date. This option implies `--force-rebase`.
+
 --ignore-date::
-	These flags are passed to 'git am' to easily change the dates
-	of the rebased commits (see linkgit:git-am[1]).
+	This flag is passed to 'git am' to change the author date
+	of each rebased commit (see linkgit:git-am[1]).
 +
 See also INCOMPATIBLE OPTIONS below.
 
@@ -585,7 +589,6 @@ INCOMPATIBLE OPTIONS
 The following options:
 
  * --apply
- * --committer-date-is-author-date
  * --ignore-date
  * --whitespace
  * -C
@@ -613,6 +616,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --rebase-merges
  * --preserve-merges and --empty=
  * --preserve-merges and --ignore-whitespace
+ * --preserve-merges and --committer-date-is-author-date
  * --keep-base and --onto
  * --keep-base and --root
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index bd93e9742c..2579380729 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -88,6 +88,7 @@ struct rebase_options {
 	int autosquash;
 	char *gpg_sign_opt;
 	int autostash;
+	int committer_date_is_author_date;
 	char *cmd;
 	int allow_empty_message;
 	int rebase_merges, rebase_cousins;
@@ -124,6 +125,8 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 	replay.quiet = !(opts->flags & REBASE_NO_QUIET);
 	replay.verbose = opts->flags & REBASE_VERBOSE;
 	replay.reschedule_failed_exec = opts->reschedule_failed_exec;
+	replay.committer_date_is_author_date =
+					opts->committer_date_is_author_date;
 	replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
 	replay.strategy = opts->strategy;
 
@@ -1497,9 +1500,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
 		OPT_BOOL(0, "signoff", &options.signoff,
 			 N_("add a Signed-off-by: line to each commit")),
-		OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
-				  &options.git_am_opts, NULL,
-				  N_("passed to 'git am'"), PARSE_OPT_NOARG),
+		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_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
@@ -1794,11 +1797,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	    options.autosquash) {
 		allow_preemptive_ff = 0;
 	}
+	if (options.committer_date_is_author_date)
+		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, "--committer-date-is-author-date") ||
-		    !strcmp(option, "--ignore-date") ||
+		if (!strcmp(option, "--ignore-date") ||
 		    !strcmp(option, "--whitespace=fix") ||
 		    !strcmp(option, "--whitespace=strip"))
 			allow_preemptive_ff = 0;
@@ -1855,6 +1859,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		if (ignore_whitespace)
 			argv_array_push(&options.git_am_opts,
 					"--ignore-whitespace");
+		if (options.committer_date_is_author_date)
+			argv_array_push(&options.git_am_opts,
+					"--committer-date-is-author-date");
 	} else {
 		/* REBASE_MERGE and PRESERVE_MERGES */
 		if (ignore_whitespace) {
diff --git a/sequencer.c b/sequencer.c
index 968a2d4ef3..78d09f9252 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;
 
diff --git a/sequencer.h b/sequencer.h
index 0bee85093e..7ca657fe2c 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -45,9 +45,12 @@ struct replay_opts {
 	int verbose;
 	int quiet;
 	int reschedule_failed_exec;
+	int committer_date_is_author_date;
 
 	int mainline;
 
+	char *committer_name;
+	char *committer_email;
 	char *gpg_sign;
 	enum commit_msg_cleanup_mode default_msg_cleanup;
 	int explicit_cleanup;
diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index 55ca46786d..c8234062c6 100755
--- a/t/t3422-rebase-incompatible-options.sh
+++ b/t/t3422-rebase-incompatible-options.sh
@@ -61,7 +61,6 @@ test_rebase_am_only () {
 }
 
 test_rebase_am_only --whitespace=fix
-test_rebase_am_only --committer-date-is-author-date
 test_rebase_am_only -C4
 
 test_expect_success REBASE_P '--preserve-merges incompatible with --signoff' '
diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
index 4f8a6e51c9..50a63d8ebe 100755
--- a/t/t3436-rebase-more-options.sh
+++ b/t/t3436-rebase-more-options.sh
@@ -9,6 +9,9 @@ test_description='tests to ensure compatibility between am and interactive backe
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
+GIT_AUTHOR_DATE="1999-04-02T08:03:20+05:30"
+export GIT_AUTHOR_DATE
+
 # This is a special case in which both am and interactive backends
 # provide the same output. It was done intentionally because
 # both the backends fall short of optimal behaviour.
@@ -21,11 +24,20 @@ test_expect_success 'setup' '
 	test_write_lines "line 1" "new line 2" "line 3" >file &&
 	git commit -am "update file" &&
 	git tag side &&
+	test_commit commit1 foo foo1 &&
+	test_commit commit2 foo foo2 &&
+	test_commit commit3 foo foo3 &&
 
 	git checkout --orphan master &&
+	rm foo &&
 	test_write_lines "line 1" "        line 2" "line 3" >file &&
 	git commit -am "add file" &&
-	git tag main
+	git tag main &&
+
+	mkdir test-bin &&
+	write_script test-bin/git-merge-test <<-\EOF
+	exec git-merge-recursive "$@"
+	EOF
 '
 
 test_expect_success '--ignore-whitespace works with apply backend' '
@@ -52,6 +64,50 @@ test_expect_success '--ignore-whitespace is remembered when continuing' '
 	git diff --exit-code side
 '
 
+test_ctime_is_atime () {
+	git log $1 --format=%ai >authortime &&
+	git log $1 --format=%ci >committertime &&
+	test_cmp authortime committertime
+}
+
+test_expect_success '--committer-date-is-author-date works with apply backend' '
+	GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
+	git rebase --apply --committer-date-is-author-date HEAD^ &&
+	test_ctime_is_atime -1
+'
+
+test_expect_success '--committer-date-is-author-date works with merge backend' '
+	GIT_AUTHOR_DATE="@1234 +0300" git commit --amend --reset-author &&
+	git rebase -m --committer-date-is-author-date HEAD^ &&
+	test_ctime_is_atime -1
+'
+
+test_expect_success '--committer-date-is-author-date works with rebase -r' '
+	git checkout side &&
+	GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
+	git rebase -r --root --committer-date-is-author-date &&
+	test_ctime_is_atime
+'
+
+test_expect_success '--committer-date-is-author-date works when forking merge' '
+	git checkout side &&
+	GIT_AUTHOR_DATE="@1234 +0300" git merge --no-ff commit3 &&
+	PATH="./test-bin:$PATH" git rebase -r --root --strategy=test \
+					--committer-date-is-author-date &&
+	test_ctime_is_atime
+'
+
+test_expect_success '--committer-date-is-author-date works when committing conflict resolution' '
+	git checkout commit2 &&
+	GIT_AUTHOR_DATE="@1980 +0000" git commit --amend --only --reset-author &&
+	test_must_fail git rebase -m --committer-date-is-author-date \
+		--onto HEAD^^ HEAD^ &&
+	echo resolved > foo &&
+	git add foo &&
+	git rebase --continue &&
+	test_ctime_is_atime -1
+'
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged

From a3894aad67df655a9c7f3b511093f681d3a01fb7 Mon Sep 17 00:00:00 2001
From: Phillip Wood <phillip.wood@dunelm.org.uk>
Date: Mon, 17 Aug 2020 18:40:03 +0100
Subject: [PATCH 4/6] rebase -i: support --ignore-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 --ignore-date
option to the merge backend. This option uses the current time as the
author date rather than reusing the original author date when
rewriting commits. 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   |  7 ++--
 builtin/rebase.c               | 13 ++++---
 sequencer.c                    | 66 +++++++++++++++++++++++++++-------
 sequencer.h                    |  1 +
 t/t3436-rebase-more-options.sh | 56 +++++++++++++++++++++++++++++
 5 files changed, 123 insertions(+), 20 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index f9ddfe2e77..79cecd2929 100644
--- a/Documentation/git-rebase.txt
+++ b/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
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 2579380729..583ac96fc7 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -89,6 +89,7 @@ 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;
@@ -127,6 +128,7 @@ 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;
 
@@ -1503,8 +1505,8 @@ 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,
+			 N_("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", &ignore_whitespace,
@@ -1797,13 +1799,12 @@ 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)) {
@@ -1862,6 +1863,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		if (options.committer_date_is_author_date)
 			argv_array_push(&options.git_am_opts,
 					"--committer-date-is-author-date");
+		if (options.ignore_date)
+			argv_array_push(&options.git_am_opts, "--ignore-date");
 	} else {
 		/* REBASE_MERGE and PRESERVE_MERGES */
 		if (ignore_whitespace) {
diff --git a/sequencer.c b/sequencer.c
index 78d09f9252..4ccb5451a9 100644
--- a/sequencer.c
+++ b/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")
@@ -959,7 +960,11 @@ 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");
 
@@ -1434,26 +1439,51 @@ static int try_to_commit(struct repository *r,
 		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 (!opts->ignore_date) {
+			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);
+		} else {
+			reset_ident_date();
 		}
-		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,
+				      WANT_COMMITTER_IDENT,
+				      opts->ignore_date ? NULL : date.buf,
 				      IDENT_STRICT);
 		strbuf_release(&date);
 	} else {
 		reset_ident_date();
 	}
 
+	if (opts->ignore_date) {
+		struct ident_split id;
+		char *name, *email;
+
+		if (split_ident_line(&id, author, strlen(author)) < 0) {
+			error(_("invalid author identity '%s'"), author);
+			goto out;
+		}
+		name = xmemdupz(id.name_begin, id.name_end - id.name_begin);
+		email = xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
+		author = fmt_ident(name, email, WANT_AUTHOR_IDENT, NULL,
+				   IDENT_STRICT);
+		free(name);
+		free(email);
+	}
+
 	if (commit_tree_extended(msg->buf, msg->len, &tree, parents, oid,
 				 author, committer, opts->gpg_sign, extra)) {
 		res = error(_("failed to write commit object"));
@@ -2583,6 +2613,11 @@ 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;
 
@@ -2675,6 +2710,8 @@ 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", "");
 
@@ -3597,7 +3634,11 @@ 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");
@@ -3877,7 +3918,8 @@ 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;
 
diff --git a/sequencer.h b/sequencer.h
index 7ca657fe2c..20493a2be2 100644
--- a/sequencer.h
+++ b/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;
 
diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
index 50a63d8ebe..8d73639954 100755
--- a/t/t3436-rebase-more-options.sh
+++ b/t/t3436-rebase-more-options.sh
@@ -108,6 +108,62 @@ test_expect_success '--committer-date-is-author-date works when committing confl
 	test_ctime_is_atime -1
 '
 
+# Checking for +0000 in the author date is sufficient since the
+# default timezone is UTC but the timezone used while committing is
+# +0530. The inverted logic in the grep is necessary to check all the
+# author dates in the file.
+test_atime_is_ignored () {
+	git log $1 --format=%ai >authortime &&
+	! grep -v +0000 authortime
+}
+
+test_expect_success '--ignore-date works with apply backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --apply --ignore-date HEAD^ &&
+	test_atime_is_ignored -1
+'
+
+test_expect_success '--ignore-date works with merge backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --ignore-date -m HEAD^ &&
+	test_atime_is_ignored -1
+'
+
+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 &&
+	test_atime_is_ignored -1
+'
+
+test_expect_success '--ignore-date works with rebase -r' '
+	git checkout side &&
+	git merge --no-ff commit3 &&
+	git rebase -r --root --ignore-date &&
+	test_atime_is_ignored
+'
+
+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 &&
+	test_ctime_is_atime -2 &&
+	test_atime_is_ignored -2
+'
+
+test_expect_success '--ignore-date --committer-date-is-author-date works when forking merge' '
+	GIT_SEQUENCE_EDITOR="echo \"merge -C $(git rev-parse HEAD) commit3\">" \
+		PATH="./test-bin:$PATH" git rebase -i --strategy=test \
+				--ignore-date --committer-date-is-author-date \
+				side side &&
+	test_ctime_is_atime -1 &&
+	test_atime_is_ignored -1
+ '
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged

From 27126692ba1688081d8427220087bb7662594bd9 Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Mon, 17 Aug 2020 18:40:04 +0100
Subject: [PATCH 5/6] rebase: add --reset-author-date

The previous commit introduced --ignore-date flag to rebase -i, but the
name is rather vague as it does not say whether the author date or the
committer date is ignored. Add an alias to convey the precise purpose.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt   |  1 +
 builtin/rebase.c               |  4 +++-
 t/t3436-rebase-more-options.sh | 34 +++++++++++++++++++++-------------
 3 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 79cecd2929..1ee3bb4fac 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -450,6 +450,7 @@ See also INCOMPATIBLE OPTIONS below.
 	date. This option implies `--force-rebase`.
 
 --ignore-date::
+--reset-author-date::
 	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`.
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 583ac96fc7..b126fbe940 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1505,8 +1505,10 @@ 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_BOOL(0, "ignore-date", &options.ignore_date,
+		OPT_BOOL(0, "reset-author-date", &options.ignore_date,
 			 N_("ignore author date and use current date")),
+		OPT_HIDDEN_BOOL(0, "ignore-date", &options.ignore_date,
+				N_("synonym of --reset-author-date")),
 		OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
 				  N_("passed to 'git apply'"), 0),
 		OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
index 8d73639954..627fa163a2 100755
--- a/t/t3436-rebase-more-options.sh
+++ b/t/t3436-rebase-more-options.sh
@@ -117,20 +117,20 @@ test_atime_is_ignored () {
 	! grep -v +0000 authortime
 }
 
-test_expect_success '--ignore-date works with apply backend' '
+test_expect_success '--reset-author-date works with apply backend' '
 	git commit --amend --date="$GIT_AUTHOR_DATE" &&
-	git rebase --apply --ignore-date HEAD^ &&
+	git rebase --apply --reset-author-date HEAD^ &&
 	test_atime_is_ignored -1
 '
 
-test_expect_success '--ignore-date works with merge backend' '
+test_expect_success '--reset-author-date works with merge backend' '
 	git commit --amend --date="$GIT_AUTHOR_DATE" &&
-	git rebase --ignore-date -m HEAD^ &&
+	git rebase --reset-author-date -m HEAD^ &&
 	test_atime_is_ignored -1
 '
 
-test_expect_success '--ignore-date works after conflict resolution' '
-	test_must_fail git rebase --ignore-date -m \
+test_expect_success '--reset-author-date works after conflict resolution' '
+	test_must_fail git rebase --reset-author-date -m \
 		--onto commit2^^ commit2^ commit2 &&
 	echo resolved >foo &&
 	git add foo &&
@@ -138,16 +138,16 @@ test_expect_success '--ignore-date works after conflict resolution' '
 	test_atime_is_ignored -1
 '
 
-test_expect_success '--ignore-date works with rebase -r' '
+test_expect_success '--reset-author-date works with rebase -r' '
 	git checkout side &&
 	git merge --no-ff commit3 &&
-	git rebase -r --root --ignore-date &&
+	git rebase -r --root --reset-author-date &&
 	test_atime_is_ignored
 '
 
-test_expect_success '--ignore-date with --committer-date-is-author-date works' '
+test_expect_success '--reset-author-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 &&
+		--reset-author-date --onto commit2^^ commit2^ commit3 &&
 	git checkout --theirs foo &&
 	git add foo &&
 	git rebase --continue &&
@@ -155,15 +155,23 @@ test_expect_success '--ignore-date with --committer-date-is-author-date works' '
 	test_atime_is_ignored -2
 '
 
-test_expect_success '--ignore-date --committer-date-is-author-date works when forking merge' '
+test_expect_success '--reset-author-date --committer-date-is-author-date works when forking merge' '
 	GIT_SEQUENCE_EDITOR="echo \"merge -C $(git rev-parse HEAD) commit3\">" \
 		PATH="./test-bin:$PATH" git rebase -i --strategy=test \
-				--ignore-date --committer-date-is-author-date \
-				side side &&
+				--reset-author-date \
+				--committer-date-is-author-date side side &&
 	test_ctime_is_atime -1 &&
 	test_atime_is_ignored -1
  '
 
+test_expect_success '--ignore-date is an alias for --reset-author-date' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --apply --ignore-date HEAD^ &&
+	git commit --allow-empty -m empty --date="$GIT_AUTHOR_DATE" &&
+	git rebase -m --ignore-date HEAD^ &&
+	test_atime_is_ignored -2
+'
+
 # This must be the last test in this file
 test_expect_success '$EDITOR and friends are unchanged' '
 	test_editor_unchanged

From 6160b2e9a486f5dc29f621e94a0e5dcce0ab3d52 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 26 Aug 2020 14:46:23 -0700
Subject: [PATCH 6/6] t3436: do not run git-merge-recursive in dashed form

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t3436-rebase-more-options.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
index 627fa163a2..996e82787e 100755
--- a/t/t3436-rebase-more-options.sh
+++ b/t/t3436-rebase-more-options.sh
@@ -36,7 +36,7 @@ test_expect_success 'setup' '
 
 	mkdir test-bin &&
 	write_script test-bin/git-merge-test <<-\EOF
-	exec git-merge-recursive "$@"
+	exec git merge-recursive "$@"
 	EOF
 '