rebase: cleanup "--exec" option handling

index 1481c5b6a5b..a26cc0cfdb5 100644
@@ -113,7 +113,7 @@ struct rebase_options {
 	int autostash;
 	int committer_date_is_author_date;
 	int ignore_date;
-	char *cmd;
+	struct string_list exec;
 	int allow_empty_message;
 	int rebase_merges, rebase_cousins;
 	char *strategy, *strategy_opts;

@@ -131,6 +131,7 @@ struct rebase_options {
 		.default_backend = "merge",	  	\
 		.flags = REBASE_NO_QUIET, 		\
 		.git_am_opts = STRVEC_INIT,		\
+		.exec = STRING_LIST_INIT_NODUP,		\
 		.git_format_patch_opt = STRBUF_INIT,	\
 		.fork_point = -1,			\
 	}

@@ -243,17 +244,6 @@ static int init_basic_state(struct replay_opts *opts, const char *head_name,
 	return write_basic_state(opts, head_name, onto, orig_head);
 }
 
-static void split_exec_commands(const char *cmd, struct string_list *commands)
-{
-	if (cmd && *cmd) {
-		string_list_split(commands, cmd, '\n', -1);
-
-		/* rebase.c adds a new line to cmd after every command,
-		 * so here the last command is always empty */
-		string_list_remove_empty_items(commands, 0);
-	}
-}
-
 static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 {
 	int ret;

@@ -261,7 +251,6 @@ static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 	struct strvec make_script_args = STRVEC_INIT;
 	struct todo_list todo_list = TODO_LIST_INIT;
 	struct replay_opts replay = get_replay_opts(opts);
-	struct string_list commands = STRING_LIST_INIT_DUP;
 
 	if (get_revision_ranges(opts->upstream, opts->onto, &opts->orig_head->object.oid,
 				&revisions, &shortrevisions))

@@ -297,14 +286,12 @@ static int do_interactive_rebase(struct rebase_options *opts, unsigned flags)
 						&todo_list))
 			BUG("unusable todo list");
 
-		split_exec_commands(opts->cmd, &commands);
 		ret = complete_action(the_repository, &replay, flags,
 			shortrevisions, opts->onto_name, opts->onto,
-			&opts->orig_head->object.oid, &commands,
+			&opts->orig_head->object.oid, &opts->exec,
 			opts->autosquash, opts->update_refs, &todo_list);
 	}
 
-	string_list_clear(&commands, 0);
 	free(revisions);
 	free(shortrevisions);
 	todo_list_release(&todo_list);

@@ -1032,7 +1019,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	struct object_id branch_base;
 	int ignore_whitespace = 0;
 	const char *gpg_sign = NULL;
-	struct string_list exec = STRING_LIST_INIT_NODUP;
 	const char *rebase_merges = NULL;
 	struct string_list strategy_options = STRING_LIST_INIT_NODUP;
 	struct object_id squash_onto;

@@ -1127,7 +1113,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 			N_("GPG-sign commits"),
 			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
 		OPT_AUTOSTASH(&options.autostash),
-		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
+		OPT_STRING_LIST('x', "exec", &options.exec, N_("exec"),
 				N_("add exec lines after each commit of the "
 				   "editable list")),
 		OPT_BOOL_F(0, "allow-empty-message",

@@ -1250,7 +1236,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	if (trace2_is_enabled()) {
 		if (is_merge(&options))
 			trace2_cmd_mode("interactive");
-		else if (exec.nr)
+		else if (options.exec.nr)
 			trace2_cmd_mode("interactive-exec");
 		else
 			trace2_cmd_mode(action_names[options.action]);

@@ -1378,7 +1364,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	if ((options.flags & REBASE_INTERACTIVE_EXPLICIT) ||
 	    (options.action != ACTION_NONE) ||
-	    (exec.nr > 0) ||
+	    (options.exec.nr > 0) ||
 	    options.autosquash) {
 		allow_preemptive_ff = 0;
 	}

@@ -1402,8 +1388,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	for (i = 0; i < exec.nr; i++)
-		if (check_exec_cmd(exec.items[i].string))
+	for (i = 0; i < options.exec.nr; i++)
+		if (check_exec_cmd(options.exec.items[i].string))
 			exit(1);
 
 	if (!(options.flags & REBASE_NO_QUIET))

@@ -1422,17 +1408,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	if (gpg_sign)
 		options.gpg_sign_opt = xstrfmt("-S%s", gpg_sign);
 
-	if (exec.nr) {
-		int i;
-
+	if (options.exec.nr)
 		imply_merge(&options, "--exec");
 
-		strbuf_reset(&buf);
-		for (i = 0; i < exec.nr; i++)
-			strbuf_addf(&buf, "exec %s\n", exec.items[i].string);
-		options.cmd = xstrdup(buf.buf);
-	}
-
 	if (rebase_merges) {
 		if (!*rebase_merges)
 			; /* default mode; do nothing */

@@ -1543,7 +1521,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 	if (options.empty == EMPTY_UNSPECIFIED) {
 		if (options.flags & REBASE_INTERACTIVE_EXPLICIT)
 			options.empty = EMPTY_ASK;
-		else if (exec.nr > 0)
+		else if (options.exec.nr > 0)
 			options.empty = EMPTY_KEEP;
 		else
 			options.empty = EMPTY_DROP;

@@ -1831,11 +1809,10 @@ cleanup:
 	free(options.head_name);
 	strvec_clear(&options.git_am_opts);
 	free(options.gpg_sign_opt);
-	free(options.cmd);
+	string_list_clear(&options.exec, 0);
 	free(options.strategy);
 	strbuf_release(&options.git_format_patch_opt);
 	free(squash_onto_name);
-	string_list_clear(&exec, 0);
 	string_list_clear(&strategy_options, 0);
 	return !!ret;
 }

index bcb662e23be..3e4a1972897 100644
@@ -5745,8 +5745,8 @@ static void todo_list_add_exec_commands(struct todo_list *todo_list,
 
 		base_items[i].command = TODO_EXEC;
 		base_items[i].offset_in_buf = base_offset;
-		base_items[i].arg_offset = base_offset + strlen("exec ");
-		base_items[i].arg_len = command_len - strlen("exec ");
+		base_items[i].arg_offset = base_offset;
+		base_items[i].arg_len = command_len;
 
 		base_offset += command_len + 1;
 	}