[RFC PATCH 9/9] sequencer: have read_populate_todo() check for dropped commits

[Alban Gruin <alban.gruin@gmail.com>]

This adds the ability to check if commits were dropped when resuming a
rebase (with `--continue') or when reloading the todo list after an
`exec' command.

Tests added previously should work now.

Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
---
 sequencer.c                   | 5 ++++-
 t/t3404-rebase-interactive.sh | 4 ++--
 t/t3429-rebase-edit-todo.sh   | 4 ++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 0638c92f12..d2c4459e7c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -2360,7 +2360,6 @@ static int read_populate_todo(struct repository *r,
 	struct stat st;
 	const char *todo_file = get_todo_path(opts);
 	int res;
-
 	strbuf_reset(&todo_list->buf);
 	if (strbuf_read_file_or_whine(&todo_list->buf, todo_file) < 0)
 		return -1;
@@ -2378,6 +2377,10 @@ static int read_populate_todo(struct repository *r,
 		return error(_("unusable instruction sheet: '%s'"), todo_file);
 	}
 
+	res = todo_list_check_against_backup(r, todo_list);
+	if (res)
+		return -1;
+
 	if (!todo_list->nr &&
 	    (!is_rebase_i(opts) || !file_exists(rebase_path_done())))
 		return error(_("no commits parsed."));
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index f5c0a8d2bb..090a496bcc 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1373,7 +1373,7 @@ EOF
 
 tail -n 8 <expect >expect.2
 
-test_expect_failure 'rebase --edit-todo respects rebase.missingCommitsCheck = warn' '
+test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = warn' '
 	test_config rebase.missingCommitsCheck warn &&
 	rebase_setup_and_clean missing-commit &&
 	set_fake_editor &&
@@ -1405,7 +1405,7 @@ EOF
 
 tail -n 9 <expect >expect.2
 
-test_expect_failure 'rebase --edit-todo respects rebase.missingCommitsCheck = error' '
+test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = error' '
 	test_config rebase.missingCommitsCheck error &&
 	rebase_setup_and_clean missing-commit &&
 	set_fake_editor &&
diff --git a/t/t3429-rebase-edit-todo.sh b/t/t3429-rebase-edit-todo.sh
index 2bb9fb65fa..79cd5657b3 100755
--- a/t/t3429-rebase-edit-todo.sh
+++ b/t/t3429-rebase-edit-todo.sh
@@ -50,7 +50,7 @@ Use 'git config rebase.missingCommitsCheck' to change the level of warnings.
 The possible behaviours are: ignore, warn, error.
 EOF
 
-test_expect_failure 'rebase exec respects rebase.missingCommitsCheck = warn' '
+test_expect_success 'rebase exec respects rebase.missingCommitsCheck = warn' '
 	test_config rebase.missingCommitsCheck warn &&
 	git reset --hard HEAD@{2} &&
 	git rebase HEAD~2 --keep-empty -x "echo >$todo" 2>actual.2 &&
@@ -59,7 +59,7 @@ test_expect_failure 'rebase exec respects rebase.missingCommitsCheck = warn' '
 	test 5 = $(git cat-file commit HEAD | sed -ne \$p)
 '
 
-test_expect_failure 'rebase exec respects rebase.missingCommitsCheck = error' '
+test_expect_success 'rebase exec respects rebase.missingCommitsCheck = error' '
 	test_config rebase.missingCommitsCheck error &&
 	git reset --hard HEAD@{2} &&
 	test_must_fail git rebase HEAD~2 --keep-empty -x "echo >$todo" 2>actual.2 &&
-- 
2.22.0