sequencer: get rid of the subcommand field

The subcommands are used exactly once, at the very beginning of
sequencer_pick_revisions(), to determine what to do. This is an
unnecessary level of indirection: we can simply call the correct
function to begin with. So let's do that.

While at it, ensure that the subcommands return an error code so that
they do not have to die() all over the place (bad practice for library
functions...).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

builtin/revert.c

@@ -71,7 +71,7 @@ static void verify_opt_compatible(const char *me, const char *base_opt, ...)
 		die(_("%s: %s cannot be used with %s"), me, this_opt, base_opt);
 }
 
-static void parse_args(int argc, const char **argv, struct replay_opts *opts)
+static int run_sequencer(int argc, const char **argv, struct replay_opts *opts)
 {
 	const char * const * usage_str = revert_or_cherry_pick_usage(opts);
 	const char *me = action_name(opts);
@@ -121,25 +121,15 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 	if (opts->keep_redundant_commits)
 		opts->allow_empty = 1;
 
-	/* Set the subcommand */
-	if (cmd == 'q')
-		opts->subcommand = REPLAY_REMOVE_STATE;
-	else if (cmd == 'c')
-		opts->subcommand = REPLAY_CONTINUE;
-	else if (cmd == 'a')
-		opts->subcommand = REPLAY_ROLLBACK;
-	else
-		opts->subcommand = REPLAY_NONE;
-
 	/* Check for incompatible command line arguments */
-	if (opts->subcommand != REPLAY_NONE) {
+	if (cmd) {
 		char *this_operation;
-		if (opts->subcommand == REPLAY_REMOVE_STATE)
+		if (cmd == 'q')
 			this_operation = "--quit";
-		else if (opts->subcommand == REPLAY_CONTINUE)
+		else if (cmd == 'c')
 			this_operation = "--continue";
 		else {
-			assert(opts->subcommand == REPLAY_ROLLBACK);
+			assert(cmd == 'a');
 			this_operation = "--abort";
 		}
 
@@ -162,7 +152,7 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 				"--edit", opts->edit,
 				NULL);
 
-	if (opts->subcommand != REPLAY_NONE) {
+	if (cmd) {
 		opts->revs = NULL;
 	} else {
 		struct setup_revision_opt s_r_opt;
@@ -180,6 +170,14 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 
 	if (argc > 1)
 		usage_with_options(usage_str, options);
+
+	if (cmd == 'q')
+		return sequencer_remove_state(opts);
+	if (cmd == 'c')
+		return sequencer_continue(opts);
+	if (cmd == 'a')
+		return sequencer_rollback(opts);
+	return sequencer_pick_revisions(opts);
 }
 
 int cmd_revert(int argc, const char **argv, const char *prefix)
@@ -191,8 +189,7 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 		opts.edit = 1;
 	opts.action = REPLAY_REVERT;
 	git_config(git_default_config, NULL);
-	parse_args(argc, argv, &opts);
-	res = sequencer_pick_revisions(&opts);
+	res = run_sequencer(argc, argv, &opts);
 	if (res < 0)
 		die(_("revert failed"));
 	return res;
@@ -205,8 +202,7 @@ int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 
 	opts.action = REPLAY_PICK;
 	git_config(git_default_config, NULL);
-	parse_args(argc, argv, &opts);
-	res = sequencer_pick_revisions(&opts);
+	res = run_sequencer(argc, argv, &opts);
 	if (res < 0)
 		die(_("cherry-pick failed"));
 	return res;

sequencer.c

@@ -134,13 +134,15 @@ static int has_conforming_footer(struct strbuf *sb, struct strbuf *sob,
 	return 1;
 }
 
-static void remove_sequencer_state(const struct replay_opts *opts)
+int sequencer_remove_state(struct replay_opts *opts)
 {
 	struct strbuf dir = STRBUF_INIT;
 
 	strbuf_addf(&dir, "%s", get_dir(opts));
 	remove_dir_recursively(&dir, 0);
 	strbuf_release(&dir);
+
+	return 0;
 }
 
 static const char *action_name(const struct replay_opts *opts)
@@ -941,12 +943,15 @@ static int rollback_single_pick(void)
 	return reset_for_rollback(head_sha1);
 }
 
-static int sequencer_rollback(struct replay_opts *opts)
+int sequencer_rollback(struct replay_opts *opts)
 {
 	FILE *f;
 	unsigned char sha1[20];
 	struct strbuf buf = STRBUF_INIT;
 
+	if (read_and_refresh_cache(opts))
+		return -1;
+
 	f = fopen(git_path_head_file(), "r");
 	if (!f && errno == ENOENT) {
 		/*
@@ -973,9 +978,8 @@ static int sequencer_rollback(struct replay_opts *opts)
 	}
 	if (reset_for_rollback(sha1))
 		goto fail;
-	remove_sequencer_state(opts);
 	strbuf_release(&buf);
-	return 0;
+	return sequencer_remove_state(opts);
 fail:
 	strbuf_release(&buf);
 	return -1;
@@ -1062,8 +1066,7 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 	 * Sequence of picks finished successfully; cleanup by
 	 * removing the .git/sequencer directory
 	 */
-	remove_sequencer_state(opts);
-	return 0;
+	return sequencer_remove_state(opts);
 }
 
 static int continue_single_pick(void)
@@ -1076,11 +1079,14 @@ static int continue_single_pick(void)
 	return run_command_v_opt(argv, RUN_GIT_CMD);
 }
 
-static int sequencer_continue(struct replay_opts *opts)
+int sequencer_continue(struct replay_opts *opts)
 {
 	struct todo_list todo_list = TODO_LIST_INIT;
 	int res;
 
+	if (read_and_refresh_cache(opts))
+		return -1;
+
 	if (!file_exists(get_todo_path(opts)))
 		return continue_single_pick();
 	if (read_populate_opts(opts) ||
@@ -1116,26 +1122,10 @@ int sequencer_pick_revisions(struct replay_opts *opts)
 	unsigned char sha1[20];
 	int i, res;
 
-	if (opts->subcommand == REPLAY_NONE)
-		assert(opts->revs);
-
+	assert(opts->revs);
 	if (read_and_refresh_cache(opts))
 		return -1;
 
-	/*
-	 * Decide what to do depending on the arguments; a fresh
-	 * cherry-pick should be handled differently from an existing
-	 * one that is being continued
-	 */
-	if (opts->subcommand == REPLAY_REMOVE_STATE) {
-		remove_sequencer_state(opts);
-		return 0;
-	}
-	if (opts->subcommand == REPLAY_ROLLBACK)
-		return sequencer_rollback(opts);
-	if (opts->subcommand == REPLAY_CONTINUE)
-		return sequencer_continue(opts);
-
 	for (i = 0; i < opts->revs->pending.nr; i++) {
 		unsigned char sha1[20];
 		const char *name = opts->revs->pending.objects[i].name;

sequencer.h

@@ -11,17 +11,8 @@ enum replay_action {
 	REPLAY_INTERACTIVE_REBASE
 };
 
-enum replay_subcommand {
-	REPLAY_NONE,
-	REPLAY_REMOVE_STATE,
-	REPLAY_CONTINUE,
-	REPLAY_ROLLBACK,
-	REPLAY_SKIP
-};
-
 struct replay_opts {
 	enum replay_action action;
-	enum replay_subcommand subcommand;
 
 	/* Boolean options */
 	int edit;
@@ -46,9 +37,12 @@ struct replay_opts {
 	/* Only used by REPLAY_NONE */
 	struct rev_info *revs;
 };
-#define REPLAY_OPTS_INIT { -1, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, NULL, 0, 0, NULL }
+#define REPLAY_OPTS_INIT { -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, NULL, 0, 0, NULL }
 
 int sequencer_pick_revisions(struct replay_opts *opts);
+int sequencer_continue(struct replay_opts *opts);
+int sequencer_rollback(struct replay_opts *opts);
+int sequencer_remove_state(struct replay_opts *opts);
 
 extern const char sign_off_header[];