It is silly for cmd_list_parse to return an integer error when it could

just return NULL.

cfg.c

@@ -141,7 +141,8 @@ load_cfg(const char *path, struct client *c, struct cmdq_item *item, int quiet)
 		if (condition == -1)
 			continue;
 
-		if (cmd_string_parse(p, &cmdlist, path, line, &cause1) != 0) {
+		cmdlist = cmd_string_parse(p, path, line, &cause1);
+		if (cmdlist == NULL) {
 			free(buf);
 			if (cause1 == NULL)
 				continue;

cmd-command-prompt.c

@@ -175,7 +175,8 @@ cmd_command_prompt_callback(void *data, const char *s, int done)
 		return (1);
 	}
 
-	if (cmd_string_parse(new_template, &cmdlist, NULL, 0, &cause) != 0) {
+	cmdlist = cmd_string_parse(new_template, NULL, 0, &cause);
+	if (cmdlist == NULL) {
 		if (cause != NULL) {
 			new_item = cmdq_get_callback(cmd_command_prompt_error,
 			    cause);

cmd-confirm-before.c

@@ -112,7 +112,8 @@ cmd_confirm_before_callback(void *data, const char *s, __unused int done)
 	if (tolower((u_char) s[0]) != 'y' || s[1] != '\0')
 		return (0);
 
-	if (cmd_string_parse(cdata->cmd, &cmdlist, NULL, 0, &cause) != 0) {
+	cmdlist = cmd_string_parse(cdata->cmd, NULL, 0, &cause);
+	if (cmdlist == NULL) {
 		if (cause != NULL) {
 			new_item = cmdq_get_callback(cmd_confirm_before_error,
 			    cause);

cmd-display-panes.c

@@ -90,7 +90,8 @@ cmd_display_panes_callback(struct client *c, struct window_pane *wp)
 	xasprintf(&expanded, "%%%u", wp->id);
 	cmd = cmd_template_replace(template, expanded, 1);
 
-	if (cmd_string_parse(cmd, &cmdlist, NULL, 0, &cause) != 0) {
+	cmdlist = cmd_string_parse(cmd, NULL, 0, &cause);
+	if (cmdlist == NULL) {
 		if (cause != NULL) {
 			new_item = cmdq_get_callback(cmd_display_panes_error,
 			    cause);

cmd-if-shell.c

@@ -96,7 +96,8 @@ cmd_if_shell_exec(struct cmd *self, struct cmdq_item *item)
 		free(shellcmd);
 		if (cmd == NULL)
 			return (CMD_RETURN_NORMAL);
-		if (cmd_string_parse(cmd, &cmdlist, NULL, 0, &cause) != 0) {
+		cmdlist = cmd_string_parse(cmd, NULL, 0, &cause);
+		if (cmdlist == NULL) {
 			if (cause != NULL) {
 				cmdq_error(item, "%s", cause);
 				free(cause);
@@ -167,7 +168,8 @@ cmd_if_shell_callback(struct job *job)
 	if (cmd == NULL)
 		goto out;
 
-	if (cmd_string_parse(cmd, &cmdlist, file, line, &cause) != 0) {
+	cmdlist = cmd_string_parse(cmd, file, line, &cause);
+	if (cmdlist == NULL) {
 		if (cause != NULL)
 			new_item = cmdq_get_callback(cmd_if_shell_error, cause);
 		else

cmd-set-hook.c

@@ -115,7 +115,8 @@ cmd_set_hook_exec(struct cmd *self, struct cmdq_item *item)
 		cmdq_error(item, "no command to set hook: %s", name);
 		return (CMD_RETURN_ERROR);
 	}
-	if (cmd_string_parse(cmd, &cmdlist, NULL, 0, &cause) != 0) {
+	cmdlist = cmd_string_parse(cmd, NULL, 0, &cause);
+	if (cmdlist == NULL) {
 		if (cause != NULL) {
 			cmdq_error(item, "%s", cause);
 			free(cause);

cmd-string.c

@@ -54,32 +54,17 @@ cmd_string_ungetc(size_t *p)
 	(*p)--;
 }
 
-/*
- * Parse command string. Returns -1 on error. If returning -1, cause is error
- * string, or NULL for empty command.
- */
-int
-cmd_string_parse(const char *s, struct cmd_list **cmdlist, const char *file,
-    u_int line, char **cause)
+struct cmd_list *
+cmd_string_parse(const char *s, const char *file, u_int line, char **cause)
 {
-	size_t		p;
-	int		ch, i, argc, rval;
-	char	      **argv, *buf, *t;
-	const char     *whitespace, *equals;
-	size_t		len;
-
-	argv = NULL;
-	argc = 0;
-
-	buf = NULL;
-	len = 0;
+	size_t		  p = 0;
+	int		  ch, i, argc = 0;
+	char		**argv = NULL, *buf = NULL, *t;
+	const char	 *whitespace, *equals;
+	size_t		  len = 0;
+	struct cmd_list	 *cmdlist = NULL;
 
 	*cause = NULL;
-
-	*cmdlist = NULL;
-	rval = -1;
-
-	p = 0;
 	for (;;) {
 		ch = cmd_string_getc(s, &p);
 		switch (ch) {
@@ -133,12 +118,7 @@ cmd_string_parse(const char *s, struct cmd_list **cmdlist, const char *file,
 			if (argc == 0)
 				goto out;
 
-			*cmdlist = cmd_list_parse(argc, argv, file, line,
-			    cause);
-			if (*cmdlist == NULL)
-				goto out;
-
-			rval = 0;
+			cmdlist = cmd_list_parse(argc, argv, file, line, cause);
 			goto out;
 		case '~':
 			if (buf == NULL) {
@@ -171,7 +151,7 @@ out:
 		free(argv);
 	}
 
-	return (rval);
+	return (cmdlist);
 }
 
 static void

control.c

@@ -85,7 +85,8 @@ control_callback(struct client *c, int closed, __unused void *data)
 			break;
 		}
 
-		if (cmd_string_parse(line, &cmdlist, NULL, 0, &cause) != 0) {
+		cmdlist = cmd_string_parse(line, NULL, 0, &cause);
+		if (cmdlist == NULL) {
 			item = cmdq_get_callback(control_error, cause);
 			cmdq_append(c, item);
 		} else {

key-bindings.c

@@ -379,12 +379,10 @@ key_bindings_init(void)
 	u_int		 i;
 	struct cmd_list	*cmdlist;
 	char		*cause;
-	int		 error;
 
 	for (i = 0; i < nitems(defaults); i++) {
-		error = cmd_string_parse(defaults[i], &cmdlist,
-		    "<default-keys>", i, &cause);
-		if (error != 0)
+		cmdlist = cmd_string_parse(defaults[i], "<default>", i, &cause);
+		if (cmdlist == NULL)
 			fatalx("bad default key");
 		cmdq_append(NULL, cmdq_get_command(cmdlist, NULL, NULL, 0));
 		cmd_list_free(cmdlist);

tmux.h

@@ -1823,8 +1823,7 @@ void printflike(2, 3) cmdq_print(struct cmdq_item *, const char *, ...);
 void printflike(2, 3) cmdq_error(struct cmdq_item *, const char *, ...);
 
 /* cmd-string.c */
-int	cmd_string_parse(const char *, struct cmd_list **, const char *,
-	    u_int, char **);
+struct cmd_list	*cmd_string_parse(const char *, const char *, u_int, char **);
 
 /* cmd-wait-for.c */
 void	cmd_wait_for_flush(void);

window-choose.c

@@ -255,7 +255,8 @@ window_choose_data_run(struct window_choose_data *cdata)
 	if (cdata->command == NULL)
 		return;
 
-	if (cmd_string_parse(cdata->command, &cmdlist, NULL, 0, &cause) != 0) {
+	cmdlist = cmd_string_parse(cdata->command, NULL, 0, &cause);
+	if (cmdlist == NULL) {
 		if (cause != NULL) {
 			*cause = toupper((u_char) *cause);
 			status_message_set(cdata->start_client, "%s", cause);