From b8c0b2100bbcbbfe324962b0f15c92207d945895 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Wed, 10 Oct 2018 01:53:56 -0700
Subject: [PATCH 1/2] rebase -i: clarify what happens on a failed `exec`

We had not documented previously what happens when an `exec` command in
an interactive rebase fails. Now we do.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 091eb53faa708d..d9771bd25b4a29 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -420,7 +420,8 @@ idea unless you know what you are doing (see BUGS below).
 --exec <cmd>::
 	Append "exec <cmd>" after each line creating a commit in the
 	final history. <cmd> will be interpreted as one or more shell
-	commands.
+	commands. Any command that fails will interrupt the rebase,
+	with exit code 1.
 +
 You may execute several commands by either using one instance of `--exec`
 with several commands:

From 71f82465b1c9546a09c442c3c9aa22ecbb76f820 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Fri, 12 Oct 2018 06:14:26 -0700
Subject: [PATCH 2/2] rebase -i: introduce the 'break' command

The 'edit' command can be used to cherry-pick a commit and then
immediately drop out of the interactive rebase, with exit code 0, to let
the user amend the commit, or test it, or look around.

Sometimes this functionality would come in handy *without*
cherry-picking a commit, e.g. to interrupt the interactive rebase even
before cherry-picking a commit, or immediately after an 'exec' or a
'merge'.

This commit introduces that functionality, as the spanking new 'break'
command.

Suggested-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-rebase.txt |  3 +++
 rebase-interactive.c         |  1 +
 sequencer.c                  | 24 +++++++++++++++++++++++-
 t/lib-rebase.sh              |  2 +-
 t/t3418-rebase-continue.sh   |  9 +++++++++
 5 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index d9771bd25b4a29..6b71694b0d9157 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -561,6 +561,9 @@ By replacing the command "pick" with the command "edit", you can tell
 the files and/or the commit message, amend the commit, and continue
 rebasing.
 
+To interrupt the rebase (just like an "edit" command would do, but without
+cherry-picking any commit first), use the "break" command.
+
 If you just want to edit the commit message for a commit, replace the
 command "pick" with the command "reword".
 
diff --git a/rebase-interactive.c b/rebase-interactive.c
index 0f4119cbae1bb6..78f3263fc15307 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -14,6 +14,7 @@ void append_todo_help(unsigned edit_todo, unsigned keep_empty,
 "s, squash <commit> = use commit, but meld into previous commit\n"
 "f, fixup <commit> = like \"squash\", but discard this commit's log message\n"
 "x, exec <command> = run command (the rest of the line) using shell\n"
+"b, break = stop here (continue rebase later with 'git rebase --continue')\n"
 "d, drop <commit> = remove commit\n"
 "l, label <label> = label current HEAD with a name\n"
 "t, reset <label> = reset HEAD to a label\n"
diff --git a/sequencer.c b/sequencer.c
index 8dd6db5a017030..ee3961ec63a0b3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1416,6 +1416,7 @@ enum todo_command {
 	TODO_SQUASH,
 	/* commands that do something else than handling a single commit */
 	TODO_EXEC,
+	TODO_BREAK,
 	TODO_LABEL,
 	TODO_RESET,
 	TODO_MERGE,
@@ -1437,6 +1438,7 @@ static struct {
 	{ 'f', "fixup" },
 	{ 's', "squash" },
 	{ 'x', "exec" },
+	{ 'b', "break" },
 	{ 'l', "label" },
 	{ 't', "reset" },
 	{ 'm', "merge" },
@@ -1964,7 +1966,7 @@ static int parse_insn_line(struct todo_item *item, const char *bol, char *eol)
 	padding = strspn(bol, " \t");
 	bol += padding;
 
-	if (item->command == TODO_NOOP) {
+	if (item->command == TODO_NOOP || item->command == TODO_BREAK) {
 		if (bol != eol)
 			return error(_("%s does not accept arguments: '%s'"),
 				     command_to_string(item->command), bol);
@@ -3247,6 +3249,23 @@ static int checkout_onto(struct replay_opts *opts,
 	return update_ref(NULL, "ORIG_HEAD", &oid, NULL, 0, UPDATE_REFS_MSG_ON_ERR);
 }
 
+static int stopped_at_head(void)
+{
+	struct object_id head;
+	struct commit *commit;
+	struct commit_message message;
+
+	if (get_oid("HEAD", &head) || !(commit = lookup_commit(&head)) ||
+	    parse_commit(commit) || get_message(commit, &message))
+		fprintf(stderr, _("Stopped at HEAD\n"));
+	else {
+		fprintf(stderr, _("Stopped at %s\n"), message.label);
+		free_message(commit, &message);
+	}
+	return 0;
+
+}
+
 static const char rescheduled_advice[] =
 N_("Could not execute the todo command\n"
 "\n"
@@ -3293,6 +3312,9 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 			unlink(rebase_path_stopped_sha());
 			unlink(rebase_path_amend());
 			delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
+
+			if (item->command == TODO_BREAK)
+				return stopped_at_head();
 		}
 		if (item->command <= TODO_SQUASH) {
 			if (is_rebase_i(opts))
diff --git a/t/lib-rebase.sh b/t/lib-rebase.sh
index 25a77ee5cb0408..584604ee63bd19 100644
--- a/t/lib-rebase.sh
+++ b/t/lib-rebase.sh
@@ -49,7 +49,7 @@ set_fake_editor () {
 		case $line in
 		squash|fixup|edit|reword|drop)
 			action="$line";;
-		exec*)
+		exec*|break)
 			echo "$line" | sed 's/_/ /g' >> "$1";;
 		"#")
 			echo '# comment' >> "$1";;
diff --git a/t/t3418-rebase-continue.sh b/t/t3418-rebase-continue.sh
index c145dbac38bb54..185a49108924dd 100755
--- a/t/t3418-rebase-continue.sh
+++ b/t/t3418-rebase-continue.sh
@@ -239,5 +239,14 @@ test_rerere_autoupdate -m
 GIT_SEQUENCE_EDITOR=: && export GIT_SEQUENCE_EDITOR
 test_rerere_autoupdate -i
 test_rerere_autoupdate --preserve-merges
+unset GIT_SEQUENCE_EDITOR
+
+test_expect_success 'the todo command "break" works' '
+	rm -f execed &&
+	FAKE_LINES="break exec_>execed" git rebase -i HEAD &&
+	test_path_is_missing execed &&
+	git rebase --continue &&
+	test_path_is_file execed
+'
 
 test_done