revert: stop creating and removing sequencer-old directory

Now that "git reset" no longer implicitly removes .git/sequencer that
the operator may or may not have wanted to keep, the logic to write a
backup copy of .git/sequencer and remove it when stale is not needed
any more.  Simplify the sequencer API and repository layout by
dropping it.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/revert.c

@@ -944,7 +944,7 @@ static int sequencer_rollback(struct replay_opts *opts)
 	}
 	if (reset_for_rollback(sha1))
 		goto fail;
-	remove_sequencer_state(1);
+	remove_sequencer_state();
 	strbuf_release(&buf);
 	return 0;
 fail:
@@ -1026,7 +1026,7 @@ static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
 	 * Sequence of picks finished successfully; cleanup by
 	 * removing the .git/sequencer directory
 	 */
-	remove_sequencer_state(1);
+	remove_sequencer_state();
 	return 0;
 }
 
@@ -1084,7 +1084,7 @@ static int pick_revisions(struct replay_opts *opts)
 	 * one that is being continued
 	 */
 	if (opts->subcommand == REPLAY_REMOVE_STATE) {
-		remove_sequencer_state(1);
+		remove_sequencer_state();
 		return 0;
 	}
 	if (opts->subcommand == REPLAY_ROLLBACK)

sequencer.c

@@ -3,17 +3,11 @@
 #include "strbuf.h"
 #include "dir.h"
 
-void remove_sequencer_state(int aggressive)
+void remove_sequencer_state(void)
 {
 	struct strbuf seq_dir = STRBUF_INIT;
-	struct strbuf seq_old_dir = STRBUF_INIT;
 
 	strbuf_addf(&seq_dir, "%s", git_path(SEQ_DIR));
-	strbuf_addf(&seq_old_dir, "%s", git_path(SEQ_OLD_DIR));
-	remove_dir_recursively(&seq_old_dir, 0);
-	rename(git_path(SEQ_DIR), git_path(SEQ_OLD_DIR));
-	if (aggressive)
-		remove_dir_recursively(&seq_old_dir, 0);
+	remove_dir_recursively(&seq_dir, 0);
 	strbuf_release(&seq_dir);
-	strbuf_release(&seq_old_dir);
 }

sequencer.h

@@ -2,19 +2,11 @@
 #define SEQUENCER_H
 
 #define SEQ_DIR		"sequencer"
-#define SEQ_OLD_DIR	"sequencer-old"
 #define SEQ_HEAD_FILE	"sequencer/head"
 #define SEQ_TODO_FILE	"sequencer/todo"
 #define SEQ_OPTS_FILE	"sequencer/opts"
 
-/*
- * Removes SEQ_OLD_DIR and renames SEQ_DIR to SEQ_OLD_DIR, ignoring
- * any errors.  Intended to be used by 'git reset'.
- *
- * With the aggressive flag, it additionally removes SEQ_OLD_DIR,
- * ignoring any errors.  Inteded to be used by the sequencer's
- * '--quit' subcommand.
- */
-void remove_sequencer_state(int aggressive);
+/* Removes SEQ_DIR. */
+extern void remove_sequencer_state(void);
 
 #endif