From ba51d2fb24b1a41b8cc15270a06f24c35c0fcf19 Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Fri, 1 Nov 2019 19:29:58 +0530
Subject: [PATCH 1/7] rebase -i: add --ignore-whitespace flag

There are two backends available for rebasing, viz, the am and the
interactive. Naturally, there shall be some features that are
implemented in one but not in the other. One such flag is
--ignore-whitespace which indicates merge mechanism to treat lines
with only whitespace changes as unchanged. Wire the interactive
rebase to also understand the --ignore-whitespace flag by
translating it to -Xignore-space-change.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt            | 12 ++++-
 builtin/rebase.c                        | 21 ++++++--
 t/t3422-rebase-incompatible-options.sh  |  1 -
 t/t3433-rebase-options-compatibility.sh | 65 +++++++++++++++++++++++++
 4 files changed, 91 insertions(+), 8 deletions(-)
 create mode 100755 t/t3433-rebase-options-compatibility.sh

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 5e4e927647..a70a5cab26 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -371,8 +371,16 @@ If either <upstream> or --root is given on the command line, then the
 default is `--no-fork-point`, otherwise the default is `--fork-point`.
 
 --ignore-whitespace::
+	Behaves differently depending on which backend is selected.
++
+'am' backend: When applying a patch, ignore changes in whitespace in
+context lines if necessary.
++
+'interactive' backend: Treat lines with only whitespace changes as
+unchanged for the sake of a three-way merge.
+
 --whitespace=<option>::
-	These flag 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.
 +
 See also INCOMPATIBLE OPTIONS below.
@@ -520,7 +528,6 @@ The following options:
  * --committer-date-is-author-date
  * --ignore-date
  * --whitespace
- * --ignore-whitespace
  * -C
 
 are incompatible with the following options:
@@ -543,6 +550,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --interactive
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
+ * --preserve-merges and --ignore-whitespace
  * --rebase-merges and --strategy
  * --rebase-merges and --strategy-option
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 2748fa6f2e..fb2500c716 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -79,6 +79,7 @@ struct rebase_options {
 	int allow_rerere_autoupdate;
 	int keep_empty;
 	int autosquash;
+	int ignore_whitespace;
 	char *gpg_sign_opt;
 	int autostash;
 	char *cmd;
@@ -99,6 +100,7 @@ struct rebase_options {
 
 static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 {
+	struct strbuf strategy_buf = STRBUF_INIT;
 	struct replay_opts replay = REPLAY_OPTS_INIT;
 
 	replay.action = REPLAY_INTERACTIVE_REBASE;
@@ -114,9 +116,15 @@ 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);
 
+	if (opts->strategy_opts)
+		strbuf_addstr(&strategy_buf, opts->strategy_opts);
+	if (opts->ignore_whitespace)
+		strbuf_addstr(&strategy_buf, " --ignore-space-change");
+	if (strategy_buf.len)
+		parse_strategy_opts(&replay, strategy_buf.buf);
+
+	strbuf_release(&strategy_buf);
 	return replay;
 }
 
@@ -511,6 +519,8 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, NULL, options,
 			builtin_rebase_interactive_usage, PARSE_OPT_KEEP_ARGV0);
 
+	opts.strategy_opts = xstrdup_or_null(opts.strategy_opts);
+
 	if (!is_null_oid(&squash_onto))
 		opts.squash_onto = &squash_onto;
 
@@ -964,6 +974,8 @@ static int run_am(struct rebase_options *opts)
 	am.git_cmd = 1;
 	argv_array_push(&am.args, "am");
 
+	if (opts->ignore_whitespace)
+		argv_array_push(&am.args, "--ignore-whitespace");
 	if (opts->action && !strcmp("continue", opts->action)) {
 		argv_array_push(&am.args, "--resolved");
 		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
@@ -1412,9 +1424,6 @@ 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),
@@ -1422,6 +1431,8 @@ 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", &options.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,
diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index a5868ea152..4342f79eea 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/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
new file mode 100755
index 0000000000..2e16e00a9d
--- /dev/null
+++ b/t/t3433-rebase-options-compatibility.sh
@@ -0,0 +1,65 @@
+#!/bin/sh
+#
+# Copyright (c) 2019 Rohit Ashiwal
+#
+
+test_description='tests to ensure compatibility between am and interactive backends'
+
+. ./test-lib.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 &&
+	q_to_tab >file <<-\EOF &&
+	line 1
+	Qline 2
+	line 3
+	EOF
+	git add file &&
+	git commit -m "add file" &&
+	cat >file <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	git commit -am "update file" &&
+	git tag side &&
+
+	git checkout --orphan master &&
+	sed -e "s/^|//" >file <<-\EOF &&
+	|line 1
+	|        line 2
+	|line 3
+	EOF
+	git add file &&
+	git commit -m "add file" &&
+	git tag main
+'
+
+test_expect_success '--ignore-whitespace works with am backend' '
+	cat >expect <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	test_must_fail git rebase main side &&
+	git rebase --abort &&
+	git rebase --ignore-whitespace main side &&
+	test_cmp expect file
+'
+
+test_expect_success '--ignore-whitespace works with interactive backend' '
+	cat >expect <<-\EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	test_must_fail git rebase --merge main side &&
+	git rebase --abort &&
+	git rebase --merge --ignore-whitespace main side &&
+	test_cmp expect file
+'
+
+test_done

From c068bcc59b4f16322a77b6a47b53d44b05c51fec Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Fri, 1 Nov 2019 19:29:59 +0530
Subject: [PATCH 2/7] sequencer: allow callers of read_author_script() to
 ignore fields

The current callers of the read_author_script() function read name,
email and date from the author script.  Allow callers to signal that
they are not interested in some among these three fields by passing
NULL.

Note that fields that are ignored still must exist and be formatted
correctly in the author script.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 2adcf5a639..b759c940f8 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -824,9 +824,19 @@ int read_author_script(const char *path, char **name, char **email, char **date,
 		error(_("missing 'GIT_AUTHOR_DATE'"));
 	if (date_i < 0 || email_i < 0 || date_i < 0 || err)
 		goto finish;
-	*name = kv.items[name_i].util;
-	*email = kv.items[email_i].util;
-	*date = kv.items[date_i].util;
+
+	if (name)
+		*name = kv.items[name_i].util;
+	else
+		free(kv.items[name_i].util);
+	if (email)
+		*email = kv.items[email_i].util;
+	else
+		free(kv.items[email_i].util);
+	if (date)
+		*date = kv.items[date_i].util;
+	else
+		free(kv.items[date_i].util);
 	retval = 0;
 finish:
 	string_list_clear(&kv, !!retval);

From cbd8db17acb77ea646c739bf96c31fe7484bc491 Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Fri, 1 Nov 2019 19:30:00 +0530
Subject: [PATCH 3/7] rebase -i: support --committer-date-is-author-date

rebase am already has this flag to "lie" about the committer date
by changing it to the author date. Let's add the same for
interactive machinery.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt            | 10 ++--
 builtin/rebase.c                        | 17 +++++--
 sequencer.c                             | 65 ++++++++++++++++++++++++-
 sequencer.h                             |  1 +
 t/t3422-rebase-incompatible-options.sh  |  1 -
 t/t3433-rebase-options-compatibility.sh | 37 ++++++++++++++
 6 files changed, 120 insertions(+), 11 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index a70a5cab26..b137d4f615 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -386,9 +386,13 @@ unchanged for the sake of a three-way merge.
 See also INCOMPATIBLE OPTIONS below.
 
 --committer-date-is-author-date::
+	Instead of recording the time the rebased commits are
+	created as the committer date, reuse the author date
+	as the committer date. This 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.
 
@@ -525,7 +529,6 @@ INCOMPATIBLE OPTIONS
 
 The following options:
 
- * --committer-date-is-author-date
  * --ignore-date
  * --whitespace
  * -C
@@ -551,6 +554,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
  * --preserve-merges and --ignore-whitespace
+ * --preserve-merges and --committer-date-is-author-date
  * --rebase-merges and --strategy
  * --rebase-merges and --strategy-option
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index fb2500c716..e6c6769752 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -82,6 +82,7 @@ struct rebase_options {
 	int ignore_whitespace;
 	char *gpg_sign_opt;
 	int autostash;
+	int committer_date_is_author_date;
 	char *cmd;
 	int allow_empty_message;
 	int rebase_merges, rebase_cousins;
@@ -114,6 +115,8 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
 	replay.allow_empty_message = opts->allow_empty_message;
 	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;
 
@@ -976,6 +979,8 @@ static int run_am(struct rebase_options *opts)
 
 	if (opts->ignore_whitespace)
 		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->action && !strcmp("continue", opts->action)) {
 		argv_array_push(&am.args, "--resolved");
 		argv_array_pushf(&am.args, "--resolvemsg=%s", resolvemsg);
@@ -1424,9 +1429,9 @@ 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"),
@@ -1701,10 +1706,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		    state_dir_base, cmd_live_rebase, buf.buf);
 	}
 
+	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"))
 			options.flags |= REBASE_FORCE;
diff --git a/sequencer.c b/sequencer.c
index b759c940f8..dfd7f2565f 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -147,6 +147,7 @@ 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")
@@ -879,6 +880,17 @@ static char *get_author(const char *message)
 	return NULL;
 }
 
+/* Returns a "date" string that needs to be free()'d by the caller */
+static char *read_author_date_or_null(void)
+{
+	char *date;
+
+	if (read_author_script(rebase_path_author_script(),
+			       NULL, NULL, &date, 0))
+		return NULL;
+	return date;
+}
+
 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 +950,24 @@ static int run_git_commit(struct repository *r,
 
 	cmd.git_cmd = 1;
 
+	if (opts->committer_date_is_author_date) {
+		int res = -1;
+		struct strbuf datebuf = STRBUF_INIT;
+		char *date = read_author_date_or_null();
+
+		if (!date)
+			return -1;
+
+		strbuf_addf(&datebuf, "@%s", date);
+		res = setenv("GIT_COMMITTER_DATE", datebuf.buf, 1);
+
+		strbuf_release(&datebuf);
+		free(date);
+
+		if (res)
+			return -1;
+	}
+
 	if (is_rebase_i(opts) && read_env_script(&cmd.env_array)) {
 		const char *gpg_opt = gpg_sign_opt_quoted(opts);
 
@@ -1331,7 +1361,6 @@ static int try_to_commit(struct repository *r,
 
 	if (parse_head(r, &current_head))
 		return -1;
-
 	if (flags & AMEND_MSG) {
 		const char *exclude_gpgsig[] = { "gpgsig", NULL };
 		const char *out_enc = get_commit_output_encoding();
@@ -1359,6 +1388,30 @@ static int try_to_commit(struct repository *r,
 		commit_list_insert(current_head, &parents);
 	}
 
+	if (opts->committer_date_is_author_date) {
+		int len = strlen(author);
+		struct ident_split ident;
+		struct strbuf date = STRBUF_INIT;
+
+		if (split_ident_line(&ident, author, len) < 0) {
+			res = error(_("malformed ident line"));
+			goto out;
+		}
+		if (!ident.date_begin) {
+			res = error(_("corrupted author without date information"));
+			goto out;
+		}
+
+		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);
+		strbuf_release(&date);
+
+		if (res)
+			goto out;
+	}
+
 	if (write_index_as_tree(&tree, r->index, r->index_file, 0, NULL)) {
 		res = error(_("git write-tree failed to write a tree"));
 		goto out;
@@ -2480,6 +2533,11 @@ 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;
 
@@ -2562,6 +2620,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 		write_file(rebase_path_gpg_sign_opt(), "-S%s\n", opts->gpg_sign);
 	if (opts->signoff)
 		write_file(rebase_path_signoff(), "--signoff\n");
+	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", "");
 
@@ -3650,7 +3710,8 @@ 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;
 
diff --git a/sequencer.h b/sequencer.h
index 0c494b83d4..e6cba468db 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -43,6 +43,7 @@ struct replay_opts {
 	int verbose;
 	int quiet;
 	int reschedule_failed_exec;
+	int committer_date_is_author_date;
 
 	int mainline;
 
diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index 4342f79eea..7402f7e3da 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/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
index 2e16e00a9d..a98cfe18b7 100755
--- a/t/t3433-rebase-options-compatibility.sh
+++ b/t/t3433-rebase-options-compatibility.sh
@@ -7,6 +7,9 @@ test_description='tests to ensure compatibility between am and interactive backe
 
 . ./test-lib.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.
@@ -26,8 +29,13 @@ test_expect_success 'setup' '
 	EOF
 	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 &&
+	git rm --cached foo &&
+	rm foo &&
 	sed -e "s/^|//" >file <<-\EOF &&
 	|line 1
 	|        line 2
@@ -62,4 +70,33 @@ test_expect_success '--ignore-whitespace works with interactive backend' '
 	test_cmp expect file
 '
 
+test_expect_success '--committer-date-is-author-date works with am backend' '
+	git commit --amend &&
+	git rebase --committer-date-is-author-date HEAD^ &&
+	git show HEAD --pretty="format:%ai" >authortime &&
+	git show HEAD --pretty="format:%ci" >committertime &&
+	test_cmp authortime committertime
+'
+
+test_expect_success '--committer-date-is-author-date works with interactive backend' '
+	git commit --amend &&
+	git rebase -i --committer-date-is-author-date HEAD^ &&
+	git show HEAD --pretty="format:%ai" >authortime &&
+	git show HEAD --pretty="format:%ci" >committertime &&
+	test_cmp authortime committertime
+'
+
+test_expect_success '--committer-date-is-author-date works with rebase -r' '
+	git checkout side &&
+	git merge --no-ff commit3 &&
+	git rebase -r --root --committer-date-is-author-date &&
+	git rev-list HEAD >rev_list &&
+	while read HASH
+	do
+		git show $HASH --pretty="format:%ai" >authortime
+		git show $HASH --pretty="format:%ci" >committertime
+		test_cmp authortime committertime
+	done <rev_list
+'
+
 test_done

From 0185c683c90baed447e96c18aafb705c91012b25 Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Fri, 1 Nov 2019 19:30:01 +0530
Subject: [PATCH 4/7] sequencer: rename amend_author to author_to_rename

The purpose of amend_author was to free() the malloc()'d string
obtained from get_author() while amending a commit. But we can
also use the variable to free() the author at our convenience.
Rename it to convey this meaning.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index dfd7f2565f..df239babe9 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1354,7 +1354,7 @@ static int try_to_commit(struct repository *r,
 	struct commit_extra_header *extra = NULL;
 	struct strbuf err = STRBUF_INIT;
 	struct strbuf commit_msg = STRBUF_INIT;
-	char *amend_author = NULL;
+	char *author_to_free = NULL;
 	const char *hook_commit = NULL;
 	enum commit_msg_cleanup_mode cleanup;
 	int res = 0;
@@ -1375,7 +1375,7 @@ static int try_to_commit(struct repository *r,
 			strbuf_addstr(msg, orig_message);
 			hook_commit = "HEAD";
 		}
-		author = amend_author = get_author(message);
+		author = author_to_free = get_author(message);
 		unuse_commit_buffer(current_head, message);
 		if (!author) {
 			res = error(_("unable to parse commit author"));
@@ -1474,7 +1474,7 @@ out:
 	free_commit_extra_headers(extra);
 	strbuf_release(&err);
 	strbuf_release(&commit_msg);
-	free(amend_author);
+	free(author_to_free);
 
 	return res;
 }

From 08187b4cbac2b2f870bb9c786d545b67f0262f74 Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Fri, 1 Nov 2019 19:30:02 +0530
Subject: [PATCH 5/7] rebase -i: support --ignore-date

rebase am already has this flag to "lie" about the author date
by changing it to the committer (current) date. Let's add the same
for interactive machinery.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt            |  6 +--
 builtin/rebase.c                        | 14 +++---
 sequencer.c                             | 60 +++++++++++++++++++++++--
 sequencer.h                             |  1 +
 t/t3433-rebase-options-compatibility.sh | 29 ++++++++++++
 5 files changed, 99 insertions(+), 11 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index b137d4f615..9a1eabad0f 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -391,8 +391,8 @@ See also INCOMPATIBLE OPTIONS below.
 	as the committer date. This 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 given author date, reset it to the
+	current time. This implies --force-rebase.
 +
 See also INCOMPATIBLE OPTIONS below.
 
@@ -529,7 +529,6 @@ INCOMPATIBLE OPTIONS
 
 The following options:
 
- * --ignore-date
  * --whitespace
  * -C
 
@@ -555,6 +554,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --rebase-merges
  * --preserve-merges and --ignore-whitespace
  * --preserve-merges and --committer-date-is-author-date
+ * --preserve-merges and --ignore-date
  * --rebase-merges and --strategy
  * --rebase-merges and --strategy-option
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index e6c6769752..b7d3de1a0f 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -83,6 +83,7 @@ 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;
@@ -117,6 +118,7 @@ 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;
 
@@ -981,6 +983,8 @@ 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);
@@ -1432,8 +1436,8 @@ 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,
@@ -1706,13 +1710,13 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		    state_dir_base, cmd_live_rebase, buf.buf);
 	}
 
-	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"))
 			options.flags |= REBASE_FORCE;
 		else if (skip_prefix(option, "-C", &p)) {
diff --git a/sequencer.c b/sequencer.c
index df239babe9..f53694fd0b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -148,6 +148,7 @@ 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")
@@ -891,6 +892,36 @@ static char *read_author_date_or_null(void)
 	return date;
 }
 
+/* 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"));
+		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 void push_dates(struct child_process *child, int change_committer_date)
+{
+	time_t now = time(NULL);
+	struct strbuf date = STRBUF_INIT;
+
+	strbuf_addf(&date, "@%"PRIuMAX, (uintmax_t)now);
+	argv_array_pushf(&child->env_array, "GIT_AUTHOR_DATE=%s", date.buf);
+	if (change_committer_date)
+		argv_array_pushf(&child->env_array, "GIT_COMMITTER_DATE=%s", date.buf);
+	strbuf_release(&date);
+}
+
 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"
@@ -959,7 +990,8 @@ static int run_git_commit(struct repository *r,
 			return -1;
 
 		strbuf_addf(&datebuf, "@%s", date);
-		res = setenv("GIT_COMMITTER_DATE", datebuf.buf, 1);
+		res = setenv("GIT_COMMITTER_DATE",
+			     opts->ignore_date ? "" : datebuf.buf, 1);
 
 		strbuf_release(&datebuf);
 		free(date);
@@ -983,6 +1015,8 @@ static int run_git_commit(struct repository *r,
 		argv_array_push(&cmd.args, "--amend");
 	if (opts->gpg_sign)
 		argv_array_pushf(&cmd.args, "-S%s", opts->gpg_sign);
+	if (opts->ignore_date)
+		push_dates(&cmd, opts->committer_date_is_author_date);
 	if (defmsg)
 		argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
 	else if (!(flags & EDIT_MSG))
@@ -1405,7 +1439,8 @@ 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)
@@ -1455,6 +1490,15 @@ 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"));
@@ -2538,6 +2582,11 @@ 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;
 
@@ -2622,6 +2671,8 @@ int write_basic_state(struct replay_opts *opts, const char *head_name,
 		write_file(rebase_path_signoff(), "--signoff\n");
 	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", "");
 
@@ -3439,6 +3490,8 @@ static int do_merge(struct repository *r,
 		argv_array_push(&cmd.args, git_path_merge_msg(r));
 		if (opts->gpg_sign)
 			argv_array_push(&cmd.args, opts->gpg_sign);
+		if (opts->ignore_date)
+			push_dates(&cmd, opts->committer_date_is_author_date);
 
 		/* Add the tips to be merged */
 		for (j = to_merge; j; j = j->next)
@@ -3711,7 +3764,8 @@ 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 e6cba468db..73d0515a3e 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -44,6 +44,7 @@ struct replay_opts {
 	int quiet;
 	int reschedule_failed_exec;
 	int committer_date_is_author_date;
+	int ignore_date;
 
 	int mainline;
 
diff --git a/t/t3433-rebase-options-compatibility.sh b/t/t3433-rebase-options-compatibility.sh
index a98cfe18b7..5166f158dd 100755
--- a/t/t3433-rebase-options-compatibility.sh
+++ b/t/t3433-rebase-options-compatibility.sh
@@ -99,4 +99,33 @@ test_expect_success '--committer-date-is-author-date works with rebase -r' '
 	done <rev_list
 '
 
+# 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 am backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --ignore-date HEAD^ &&
+	git show HEAD --pretty="format:%ai" >authortime &&
+	grep "+0000" authortime
+'
+
+test_expect_success '--ignore-date works with interactive backend' '
+	git commit --amend --date="$GIT_AUTHOR_DATE" &&
+	git rebase --ignore-date -i HEAD^ &&
+	git show HEAD --pretty="format:%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 rev-list HEAD >rev_list &&
+	while read HASH
+	do
+		git show $HASH --pretty="format:%ai" >authortime
+		grep "+0000" authortime
+	done <rev_list
+'
+
 test_done

From fe28ad8520a0ecac5dfcbfa019727aa6d79c36dc Mon Sep 17 00:00:00 2001
From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Date: Fri, 1 Nov 2019 19:30:03 +0530
Subject: [PATCH 6/7] rebase: add --reset-author-date

The previous commit introduced --ignore-date flag to interactive
rebase, but the name is actually very vague in context of rebase -i
since there are two dates we can work with. Add an alias to convey
the precise purpose.

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             | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 9a1eabad0f..c8d54d221d 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -391,6 +391,7 @@ See also INCOMPATIBLE OPTIONS below.
 	as the committer date. This implies --force-rebase.
 
 --ignore-date::
+--reset-author-date::
 	Instead of using the given author date, reset it to the
 	current time. This implies --force-rebase.
 +
diff --git a/builtin/rebase.c b/builtin/rebase.c
index b7d3de1a0f..44768082b8 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1436,6 +1436,8 @@ 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_BOOL(0, "reset-author-date", &options.ignore_date,
+			 "ignore author date and use current date"),
 		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"),

From d82dfa7f5b88d57cd4ddaf2c27a7218a39b9dd53 Mon Sep 17 00:00:00 2001
From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 21 Nov 2019 15:14:28 +0900
Subject: [PATCH 7/7] rebase -i: finishing touches to --reset-author-date

Clarify the way the `--reset-author-date` option is described,
and mark its usage string translatable.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt | 6 ++++--
 builtin/rebase.c             | 6 +++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index c8d54d221d..03809da835 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -392,8 +392,10 @@ See also INCOMPATIBLE OPTIONS below.
 
 --ignore-date::
 --reset-author-date::
-	Instead of using the given author date, reset it to the
-	current time. This implies --force-rebase.
+	By default, the author date of the original commit is used
+	as the author date for the resulting commit.  This option
+	tells Git to use the current timestamp instead and implies
+	`--force-rebase`.
 +
 See also INCOMPATIBLE OPTIONS below.
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 44768082b8..0ddab0bcd2 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1437,9 +1437,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			 &options.committer_date_is_author_date,
 			 N_("make committer date match author date")),
 		OPT_BOOL(0, "reset-author-date", &options.ignore_date,
-			 "ignore author date and use current date"),
-		OPT_BOOL(0, "ignore-date", &options.ignore_date,
-			 "ignore author date and use current 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", &options.ignore_whitespace,