Merge branch 'ag/edit-todo-drop-check'

Allow the rebase.missingCommitsCheck configuration to kick in when
"rebase --edit-todo" and "rebase --continue" restarts the procedure.

* ag/edit-todo-drop-check:
  rebase-interactive: warn if commit is dropped with `rebase --edit-todo'
  sequencer: move check_todo_list_from_file() to rebase-interactive.c

5 files changed, 214 insertions, 49 deletions

diff --git a/rebase-interactive.c b/rebase-interactive.c
index 1259adc8ea..ac001dea58 100644
--- a/rebase-interactive.c
+++ b/rebase-interactive.c
@@ -5,6 +5,13 @@
 #include "strbuf.h"
 #include "commit-slab.h"
 #include "config.h"
+#include "dir.h"
+
+static const char edit_todo_list_advice[] =
+N_("You can fix this with 'git rebase --edit-todo' "
+"and then run 'git rebase --continue'.\n"
+"Or you can abort the rebase with 'git rebase"
+" --abort'.\n");
 
 enum missing_commit_check_level {
 	MISSING_COMMIT_CHECK_IGNORE = 0,
@@ -91,21 +98,24 @@ int edit_todo_list(struct repository *r, struct todo_list *todo_list,
 		   struct todo_list *new_todo, const char *shortrevisions,
 		   const char *shortonto, unsigned flags)
 {
-	const char *todo_file = rebase_path_todo();
+	const char *todo_file = rebase_path_todo(),
+		*todo_backup = rebase_path_todo_backup();
 	unsigned initial = shortrevisions && shortonto;
+	int incorrect = 0;
 
 	/* If the user is editing the todo list, we first try to parse
 	 * it.  If there is an error, we do not return, because the user
 	 * might want to fix it in the first place. */
 	if (!initial)
-		todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list);
+		incorrect = todo_list_parse_insn_buffer(r, todo_list->buf.buf, todo_list) |
+			file_exists(rebase_path_dropped());
 
 	if (todo_list_write_to_file(r, todo_list, todo_file, shortrevisions, shortonto,
 				    -1, flags | TODO_LIST_SHORTEN_IDS | TODO_LIST_APPEND_TODO_HELP))
 		return error_errno(_("could not write '%s'"), todo_file);
 
-	if (initial &&
-	    todo_list_write_to_file(r, todo_list, rebase_path_todo_backup(),
+	if (!incorrect &&
+	    todo_list_write_to_file(r, todo_list, todo_backup,
 				    shortrevisions, shortonto, -1,
 				    (flags | TODO_LIST_APPEND_TODO_HELP) & ~TODO_LIST_SHORTEN_IDS) < 0)
 		return error(_("could not write '%s'."), rebase_path_todo_backup());
@@ -117,10 +127,23 @@ int edit_todo_list(struct repository *r, struct todo_list *todo_list,
 	if (initial && new_todo->buf.len == 0)
 		return -3;
 
-	/* For the initial edit, the todo list gets parsed in
-	 * complete_action(). */
-	if (!initial)
-		return todo_list_parse_insn_buffer(r, new_todo->buf.buf, new_todo);
+	if (todo_list_parse_insn_buffer(r, new_todo->buf.buf, new_todo)) {
+		fprintf(stderr, _(edit_todo_list_advice));
+		return -4;
+	}
+
+	if (incorrect) {
+		if (todo_list_check_against_backup(r, new_todo)) {
+			write_file(rebase_path_dropped(), "");
+			return -4;
+		}
+
+		if (incorrect > 0)
+			unlink(rebase_path_dropped());
+	} else if (todo_list_check(todo_list, new_todo)) {
+		write_file(rebase_path_dropped(), "");
+		return -4;
+	}
 
 	return 0;
 }
@@ -185,7 +208,52 @@ int todo_list_check(struct todo_list *old_todo, struct todo_list *new_todo)
 		"the level of warnings.\n"
 		"The possible behaviours are: ignore, warn, error.\n\n"));
 
+	fprintf(stderr, _(edit_todo_list_advice));
+
 leave_check:
 	clear_commit_seen(&commit_seen);
 	return res;
 }
+
+int todo_list_check_against_backup(struct repository *r, struct todo_list *todo_list)
+{
+	struct todo_list backup = TODO_LIST_INIT;
+	int res = 0;
+
+	if (strbuf_read_file(&backup.buf, rebase_path_todo_backup(), 0) > 0) {
+		todo_list_parse_insn_buffer(r, backup.buf.buf, &backup);
+		res = todo_list_check(&backup, todo_list);
+	}
+
+	todo_list_release(&backup);
+	return res;
+}
+
+int check_todo_list_from_file(struct repository *r)
+{
+	struct todo_list old_todo = TODO_LIST_INIT, new_todo = TODO_LIST_INIT;
+	int res = 0;
+
+	if (strbuf_read_file(&new_todo.buf, rebase_path_todo(), 0) < 0) {
+		res = error(_("could not read '%s'."), rebase_path_todo());
+		goto out;
+	}
+
+	if (strbuf_read_file(&old_todo.buf, rebase_path_todo_backup(), 0) < 0) {
+		res = error(_("could not read '%s'."), rebase_path_todo_backup());
+		goto out;
+	}
+
+	res = todo_list_parse_insn_buffer(r, old_todo.buf.buf, &old_todo);
+	if (!res)
+		res = todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo);
+	if (res)
+		fprintf(stderr, _(edit_todo_list_advice));
+	if (!res)
+		res = todo_list_check(&old_todo, &new_todo);
+out:
+	todo_list_release(&old_todo);
+	todo_list_release(&new_todo);
+
+	return res;
+}
diff --git a/rebase-interactive.h b/rebase-interactive.h
index 44dbb06311..4af0c1fcc7 100644
--- a/rebase-interactive.h
+++ b/rebase-interactive.h
@@ -11,6 +11,11 @@ void append_todo_help(unsigned keep_empty, int command_count,
 int edit_todo_list(struct repository *r, struct todo_list *todo_list,
 		   struct todo_list *new_todo, const char *shortrevisions,
 		   const char *shortonto, unsigned flags);
+
 int todo_list_check(struct todo_list *old_todo, struct todo_list *new_todo);
+int todo_list_check_against_backup(struct repository *r,
+				   struct todo_list *todo_list);
+
+int check_todo_list_from_file(struct repository *r);
 
 #endif
diff --git a/sequencer.c b/sequencer.c
index 18b2b1f4ca..ba90a513b9 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -57,6 +57,8 @@ static GIT_PATH_FUNC(rebase_path, "rebase-merge")
 GIT_PATH_FUNC(rebase_path_todo, "rebase-merge/git-rebase-todo")
 GIT_PATH_FUNC(rebase_path_todo_backup, "rebase-merge/git-rebase-todo.backup")
 
+GIT_PATH_FUNC(rebase_path_dropped, "rebase-merge/dropped")
+
 /*
  * The rebase command lines that have already been processed. A line
  * is moved here when it is first handled, before any associated user
@@ -4225,6 +4227,14 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
 	if (is_rebase_i(opts)) {
 		if ((res = read_populate_todo(r, &todo_list, opts)))
 			goto release_todo_list;
+
+		if (file_exists(rebase_path_dropped())) {
+			if ((res = todo_list_check_against_backup(r, &todo_list)))
+				goto release_todo_list;
+
+			unlink(rebase_path_dropped());
+		}
+
 		if (commit_staged_changes(r, opts, &todo_list)) {
 			res = -1;
 			goto release_todo_list;
@@ -4971,41 +4981,6 @@ int todo_list_write_to_file(struct repository *r, struct todo_list *todo_list,
 	return res;
 }
 
-static const char edit_todo_list_advice[] =
-N_("You can fix this with 'git rebase --edit-todo' "
-"and then run 'git rebase --continue'.\n"
-"Or you can abort the rebase with 'git rebase"
-" --abort'.\n");
-
-int check_todo_list_from_file(struct repository *r)
-{
-	struct todo_list old_todo = TODO_LIST_INIT, new_todo = TODO_LIST_INIT;
-	int res = 0;
-
-	if (strbuf_read_file_or_whine(&new_todo.buf, rebase_path_todo()) < 0) {
-		res = -1;
-		goto out;
-	}
-
-	if (strbuf_read_file_or_whine(&old_todo.buf, rebase_path_todo_backup()) < 0) {
-		res = -1;
-		goto out;
-	}
-
-	res = todo_list_parse_insn_buffer(r, old_todo.buf.buf, &old_todo);
-	if (!res)
-		res = todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo);
-	if (!res)
-		res = todo_list_check(&old_todo, &new_todo);
-	if (res)
-		fprintf(stderr, _(edit_todo_list_advice));
-out:
-	todo_list_release(&old_todo);
-	todo_list_release(&new_todo);
-
-	return res;
-}
-
 /* skip picking commits whose parents are unchanged */
 static int skip_unnecessary_picks(struct repository *r,
 				  struct todo_list *todo_list,
@@ -5103,11 +5078,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 		todo_list_release(&new_todo);
 
 		return error(_("nothing to do"));
-	}
-
-	if (todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo) ||
-	    todo_list_check(todo_list, &new_todo)) {
-		fprintf(stderr, _(edit_todo_list_advice));
+	} else if (res == -4) {
 		checkout_onto(r, opts, onto_name, &onto->object.oid, orig_head);
 		todo_list_release(&new_todo);
 
diff --git a/sequencer.h b/sequencer.h
index 74f1e2673e..393571e89a 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -11,6 +11,7 @@ const char *git_path_commit_editmsg(void);
 const char *git_path_seq_dir(void);
 const char *rebase_path_todo(void);
 const char *rebase_path_todo_backup(void);
+const char *rebase_path_dropped(void);
 
 #define APPEND_SIGNOFF_DEDUP (1u << 0)
 
@@ -155,7 +156,6 @@ int sequencer_make_script(struct repository *r, struct strbuf *out, int argc,
 
 void todo_list_add_exec_commands(struct todo_list *todo_list,
 				 struct string_list *commands);
-int check_todo_list_from_file(struct repository *r);
 int complete_action(struct repository *r, struct replay_opts *opts, unsigned flags,
 		    const char *shortrevisions, const char *onto_name,
 		    struct commit *onto, const char *orig_head, struct string_list *commands,
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index b90ea0fe44..d79a3ef505 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -1463,6 +1463,127 @@ test_expect_success 'rebase -i respects rebase.missingCommitsCheck = error' '
 	test B = $(git cat-file commit HEAD^ | sed -ne \$p)
 '
 
+test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = ignore' '
+	test_config rebase.missingCommitsCheck ignore &&
+	rebase_setup_and_clean missing-commit &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="break 1 2 3 4 5" git rebase -i --root &&
+		FAKE_LINES="1 2 3 4" git rebase --edit-todo &&
+		git rebase --continue 2>actual
+	) &&
+	test D = $(git cat-file commit HEAD | sed -ne \$p) &&
+	test_i18ngrep \
+		"Successfully rebased and updated refs/heads/missing-commit" \
+		actual
+'
+
+test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = warn' '
+	cat >expect <<-EOF &&
+	error: invalid line 1: badcmd $(git rev-list --pretty=oneline --abbrev-commit -1 master~4)
+	Warning: some commits may have been dropped accidentally.
+	Dropped commits (newer to older):
+	 - $(git rev-list --pretty=oneline --abbrev-commit -1 master)
+	 - $(git rev-list --pretty=oneline --abbrev-commit -1 master~4)
+	To avoid this message, use "drop" to explicitly remove a commit.
+	EOF
+	head -n4 expect >expect.2 &&
+	tail -n1 expect >>expect.2 &&
+	tail -n4 expect.2 >expect.3 &&
+	test_config rebase.missingCommitsCheck warn &&
+	rebase_setup_and_clean missing-commit &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="bad 1 2 3 4 5" \
+			git rebase -i --root &&
+		cp .git/rebase-merge/git-rebase-todo.backup orig &&
+		FAKE_LINES="2 3 4" git rebase --edit-todo 2>actual.2 &&
+		head -n6 actual.2 >actual &&
+		test_i18ncmp expect actual &&
+		cp orig .git/rebase-merge/git-rebase-todo &&
+		FAKE_LINES="1 2 3 4" git rebase --edit-todo 2>actual.2 &&
+		head -n4 actual.2 >actual &&
+		test_i18ncmp expect.3 actual &&
+		git rebase --continue 2>actual
+	) &&
+	test D = $(git cat-file commit HEAD | sed -ne \$p) &&
+	test_i18ngrep \
+		"Successfully rebased and updated refs/heads/missing-commit" \
+		actual
+'
+
+test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = error' '
+	cat >expect <<-EOF &&
+	error: invalid line 1: badcmd $(git rev-list --pretty=oneline --abbrev-commit -1 master~4)
+	Warning: some commits may have been dropped accidentally.
+	Dropped commits (newer to older):
+	 - $(git rev-list --pretty=oneline --abbrev-commit -1 master)
+	 - $(git rev-list --pretty=oneline --abbrev-commit -1 master~4)
+	To avoid this message, use "drop" to explicitly remove a commit.
+
+	Use '\''git config rebase.missingCommitsCheck'\'' to change the level of warnings.
+	The possible behaviours are: ignore, warn, error.
+
+	You can fix this with '\''git rebase --edit-todo'\'' and then run '\''git rebase --continue'\''.
+	Or you can abort the rebase with '\''git rebase --abort'\''.
+	EOF
+	tail -n11 expect >expect.2 &&
+	head -n3 expect.2 >expect.3 &&
+	tail -n7 expect.2 >>expect.3 &&
+	test_config rebase.missingCommitsCheck error &&
+	rebase_setup_and_clean missing-commit &&
+	(
+		set_fake_editor &&
+		test_must_fail env FAKE_LINES="bad 1 2 3 4 5" \
+			git rebase -i --root &&
+		cp .git/rebase-merge/git-rebase-todo.backup orig &&
+		test_must_fail env FAKE_LINES="2 3 4" \
+			git rebase --edit-todo 2>actual &&
+		test_i18ncmp expect actual &&
+		test_must_fail git rebase --continue 2>actual &&
+		test_i18ncmp expect.2 actual &&
+		test_must_fail git rebase --edit-todo &&
+		cp orig .git/rebase-merge/git-rebase-todo &&
+		test_must_fail env FAKE_LINES="1 2 3 4" \
+			git rebase --edit-todo 2>actual &&
+		test_i18ncmp expect.3 actual &&
+		test_must_fail git rebase --continue 2>actual &&
+		test_i18ncmp expect.3 actual &&
+		cp orig .git/rebase-merge/git-rebase-todo &&
+		FAKE_LINES="1 2 3 4 drop 5" git rebase --edit-todo &&
+		git rebase --continue 2>actual
+	) &&
+	test D = $(git cat-file commit HEAD | sed -ne \$p) &&
+	test_i18ngrep \
+		"Successfully rebased and updated refs/heads/missing-commit" \
+		actual
+'
+
+test_expect_success 'rebase.missingCommitsCheck = error after resolving conflicts' '
+	test_config rebase.missingCommitsCheck error &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="drop 1 break 2 3 4" git rebase -i A E
+	) &&
+	git rebase --edit-todo &&
+	test_must_fail git rebase --continue &&
+	echo x >file1 &&
+	git add file1 &&
+	git rebase --continue
+'
+
+test_expect_success 'rebase.missingCommitsCheck = error when editing for a second time' '
+	test_config rebase.missingCommitsCheck error &&
+	(
+		set_fake_editor &&
+		FAKE_LINES="1 break 2 3" git rebase -i A D &&
+		cp .git/rebase-merge/git-rebase-todo todo &&
+		test_must_fail env FAKE_LINES=2 git rebase --edit-todo &&
+		GIT_SEQUENCE_EDITOR="cp todo" git rebase --edit-todo &&
+		git rebase --continue
+	)
+'
+
 test_expect_success 'respects rebase.abbreviateCommands with fixup, squash and exec' '
 	rebase_setup_and_clean abbrevcmd &&
 	test_commit "first" file1.txt "first line" first &&