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From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
To: git@vger.kernel.org, gitster@pobox.com
Cc: phillip.wood123@gmail.com, martin.agren@gmail.com,
        Johannes.Schindelin@gmx.de,
        Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Subject: [GSoC][PATCH 1/1] rebase -i: add --ignore-whitespace flag
Date: Sat, 13 Jul 2019 00:20:15 +0530
Message-Id: <20190712185015.20585-2-rohit.ashiwal265@gmail.com>
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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>
---
 Documentation/git-rebase.txt            |  9 +++-
 builtin/rebase.c                        | 24 +++++++--
 sequencer.h                             |  1 +
 t/t3422-rebase-incompatible-options.sh  |  1 -
 t/t3431-rebase-options-compatibility.sh | 66 +++++++++++++++++++++++++
 5 files changed, 95 insertions(+), 6 deletions(-)
 create mode 100755 t/t3431-rebase-options-compatibility.sh

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 5e4e92764..eda52ed82 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -371,8 +371,13 @@ 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::
+	This flag is either passed to the 'git apply' program
+	(see linkgit:git-apply[1]), or to 'git merge' program
+	(see linkgit:git-merge[1]) as `-Xignore-space-change`,
+	depending on which backend is selected by other options.
+
 --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 +525,6 @@ The following options:
  * --committer-date-is-author-date
  * --ignore-date
  * --whitespace
- * --ignore-whitespace
  * -C
 
 are incompatible with the following options:
@@ -543,6 +547,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --interactive
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
+ * --rebase-merges and --ignore-whitespace
  * --rebase-merges and --strategy
  * --rebase-merges and --strategy-option
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index db6ca9bd7..c55957c31 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;
@@ -376,6 +377,17 @@ static int run_rebase_interactive(struct rebase_options *opts,
 	flags |= opts->rebase_cousins > 0 ? TODO_LIST_REBASE_COUSINS : 0;
 	flags |= command == ACTION_SHORTEN_OIDS ? TODO_LIST_SHORTEN_IDS : 0;
 
+	if (opts->ignore_whitespace) {
+		struct strbuf buf = STRBUF_INIT;
+
+		if (opts->strategy_opts)
+			strbuf_addstr(&buf, opts->strategy_opts);
+
+		strbuf_addstr(&buf, " --ignore-space-change");
+		free(opts->strategy_opts);
+		opts->strategy_opts = strbuf_detach(&buf, NULL);
+	}
+
 	switch (command) {
 	case ACTION_NONE: {
 		if (!opts->onto && !opts->upstream)
@@ -489,6 +501,8 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 		{ OPTION_STRING, 'S', "gpg-sign", &opts.gpg_sign_opt, N_("key-id"),
 			N_("GPG-sign commits"),
 			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+		OPT_BOOL(0, "ignore-whitespace", &opts.ignore_whitespace,
+			 N_("ignore changes in whitespace")),
 		OPT_STRING(0, "strategy", &opts.strategy, N_("strategy"),
 			   N_("rebase strategy")),
 		OPT_STRING(0, "strategy-opts", &opts.strategy_opts, N_("strategy-opts"),
@@ -954,6 +968,8 @@ 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);
@@ -1401,9 +1417,6 @@ 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),
@@ -1411,6 +1424,8 @@ 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,
@@ -1821,6 +1836,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	}
 
 	if (options.rebase_merges) {
+		if (options.ignore_whitespace)
+			die(_("cannot combine '--rebase-merges' with "
+			      "'--ignore-whitespace'"));
 		if (strategy_options.nr)
 			die(_("cannot combine '--rebase-merges' with "
 			      "'--strategy-option'"));
diff --git a/sequencer.h b/sequencer.h
index 0c494b83d..303047a13 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -43,6 +43,7 @@ struct replay_opts {
 	int verbose;
 	int quiet;
 	int reschedule_failed_exec;
+	int ignore_whitespace;
 
 	int mainline;
 
diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index a5868ea15..4342f79ee 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/t3431-rebase-options-compatibility.sh b/t/t3431-rebase-options-compatibility.sh
new file mode 100755
index 000000000..f38ae6f5f
--- /dev/null
+++ b/t/t3431-rebase-options-compatibility.sh
@@ -0,0 +1,66 @@
+#!/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 outputs. It was done intentionally because
+# --ignore-whitespace 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" &&
+	q_to_tab >file <<-EOF &&
+	line 1
+	new line 2
+	line 3
+	EOF
+	git commit -am "update file" &&
+	git tag side &&
+
+	git checkout --orphan master &&
+	q_to_tab >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

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From: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
To: git@vger.kernel.org, gitster@pobox.com
Cc: phillip.wood123@gmail.com, martin.agren@gmail.com,
        Johannes.Schindelin@gmx.de, newren@gmail.com, t.gummerer@gmail.com,
        Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Subject: [GSoC][PATCH 2/2] rebase -i: support --committer-date-is-author-date
Date: Sat, 13 Jul 2019 00:23:57 +0530
Message-Id: <20190712185357.21211-3-rohit.ashiwal265@gmail.com>
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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>
---
 Documentation/git-rebase.txt            |  7 ++--
 builtin/rebase.c                        | 23 ++++++++++---
 sequencer.c                             | 46 ++++++++++++++++++++++++-
 sequencer.h                             |  1 +
 t/t3422-rebase-incompatible-options.sh  |  1 -
 t/t3431-rebase-options-compatibility.sh | 15 ++++++++
 6 files changed, 84 insertions(+), 9 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index eda52ed82..ddd111de6 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -383,8 +383,12 @@ default is `--no-fork-point`, otherwise the default is `--fork-point`.
 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
+	This flag is passed to 'git am' to change the author date
 	of the rebased commits (see linkgit:git-am[1]).
 +
 See also INCOMPATIBLE OPTIONS below.
@@ -522,7 +526,6 @@ INCOMPATIBLE OPTIONS
 
 The following options:
 
- * --committer-date-is-author-date
  * --ignore-date
  * --whitespace
  * -C
diff --git a/builtin/rebase.c b/builtin/rebase.c
index c55957c31..82a3f7743 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;
@@ -113,6 +114,8 @@ 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;
 	if (opts->strategy_opts)
@@ -467,6 +470,9 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 		OPT_BOOL(0, "autosquash", &opts.autosquash,
 			 N_("move commits that begin with squash!/fixup!")),
 		OPT_BOOL(0, "signoff", &opts.signoff, N_("sign commits")),
+		OPT_BOOL(0, "committer-date-is-author-date",
+			 &opts.committer_date_is_author_date,
+			 N_("make committer date match author date")),
 		OPT_BIT('v', "verbose", &opts.flags,
 			N_("display a diffstat of what changed upstream"),
 			REBASE_NO_QUIET | REBASE_VERBOSE | REBASE_DIFFSTAT),
@@ -532,6 +538,9 @@ int cmd_rebase__interactive(int argc, const char **argv, const char *prefix)
 		warning(_("--[no-]rebase-cousins has no effect without "
 			  "--rebase-merges"));
 
+	if (opts.committer_date_is_author_date)
+		opts.flags |= REBASE_FORCE;
+
 	return !!run_rebase_interactive(&opts, command);
 }
 
@@ -970,6 +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);
@@ -1417,9 +1428,9 @@ 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"),
@@ -1686,10 +1697,12 @@ 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 a2d7b0925..a65f01a42 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")
@@ -876,6 +877,18 @@ 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_die(void)
+{
+	char *date;
+
+	if (read_author_script(rebase_path_author_script(),
+			       NULL, NULL, &date, 0))
+		die(_("failed to read author date"));
+
+	return date;
+}
+
 /* Read author-script and return an ident line (author <email> timestamp) */
 static const char *read_author_ident(struct strbuf *buf)
 {
@@ -986,10 +999,17 @@ static int run_git_commit(struct repository *r,
 
 		if (res <= 0)
 			res = error_errno(_("could not read '%s'"), defmsg);
-		else
+		else {
+			if (opts->committer_date_is_author_date) {
+				char *date = read_author_date_or_die();
+				setenv("GIT_COMMITTER_DATE", date, 1);
+				free(date);
+			}
+
 			res = commit_tree(msg.buf, msg.len, cache_tree_oid,
 					  NULL, &root_commit, author,
 					  opts->gpg_sign);
+		}
 
 		strbuf_release(&msg);
 		strbuf_release(&script);
@@ -1019,6 +1039,11 @@ 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->committer_date_is_author_date) {
+		char *date = read_author_date_or_die();
+		argv_array_pushf(&cmd.env_array, "GIT_COMMITTER_DATE=%s", date);
+		free(date);
+	}
 	if (defmsg)
 		argv_array_pushl(&cmd.args, "-F", defmsg, NULL);
 	else if (!(flags & EDIT_MSG))
@@ -1467,6 +1492,12 @@ static int try_to_commit(struct repository *r,
 
 	reset_ident_date();
 
+	if (opts->committer_date_is_author_date) {
+		char *date = read_author_date_or_die();
+		setenv("GIT_COMMITTER_DATE", date, 1);
+		free(date);
+	}
+
 	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 +2569,11 @@ 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;
 
@@ -2620,6 +2656,8 @@ 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", "");
 
@@ -3437,6 +3475,12 @@ 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->committer_date_is_author_date) {
+			char *date = read_author_date_or_die();
+			argv_array_pushf(&cmd.env_array,
+					 "GIT_COMMITTER_DATE=%s", date);
+			free(date);
+		}
 
 		/* Add the tips to be merged */
 		for (j = to_merge; j; j = j->next)
diff --git a/sequencer.h b/sequencer.h
index 303047a13..0cfe184fc 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -44,6 +44,7 @@ struct replay_opts {
 	int quiet;
 	int reschedule_failed_exec;
 	int ignore_whitespace;
+	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 4342f79ee..7402f7e3d 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/t3431-rebase-options-compatibility.sh b/t/t3431-rebase-options-compatibility.sh
index f38ae6f5f..a06d55dfc 100755
--- a/t/t3431-rebase-options-compatibility.sh
+++ b/t/t3431-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 outputs. It was done intentionally because
 # --ignore-whitespace both the backends fall short of optimal
@@ -63,4 +66,16 @@ test_expect_success '--ignore-whitespace works with interactive backend' '
 	test_cmp expect file
 '
 
+test_expect_success '--committer-date-is-author-date works with interactive backend' '
+	git rebase -f HEAD^ &&
+	git cat-file commit HEAD | sed -e "/^\$/q" >head &&
+	sed -ne "/^author /s/.*> //p" head >authortime &&
+	sed -ne "/^committer /s/.*> //p" head >committertime &&
+	! test_cmp at ct &&
+	git rebase -i --committer-date-is-author-date HEAD^ &&
+	git cat-file commit HEAD | sed -e "/^\$/q" >head &&
+	sed -ne "/^committer /s/.*> //p" head >committertime &&
+	test_cmp authortime committertime
+'
+
 test_done