commands: fix workspace edge cases

sway/commands/move.c

@@ -107,8 +107,13 @@ static struct cmd_results *cmd_move_container(struct sway_container *current,
 				strcasecmp(argv[2], "current") == 0) {
 			ws = workspace_by_name(argv[2]);
 		} else if (strcasecmp(argv[2], "back_and_forth") == 0) {
-			if (!(ws = workspace_by_name(argv[0])) && prev_workspace_name) {
+			if (!(ws = workspace_by_name(argv[2]))) {
-				ws = workspace_create(NULL, prev_workspace_name);
+				if (prev_workspace_name) {
+					ws = workspace_create(NULL, prev_workspace_name);
+				} else {
+					return cmd_results_new(CMD_FAILURE, "move",
+							"No workspace was previously active.");
+				}
 			}
 		} else {
 			char *ws_name = NULL;

sway/commands/rename.c

@@ -61,6 +61,16 @@ struct cmd_results *cmd_rename(int argc, char **argv) {
 	}
 
 	char *new_name = join_args(argv + argn, argc - argn);
+	if (strcasecmp(new_name, "next") == 0 ||
+			strcasecmp(new_name, "prev") == 0 ||
+			strcasecmp(new_name, "next_on_output") == 0 ||
+			strcasecmp(new_name, "prev_on_output") == 0 ||
+			strcasecmp(new_name, "back_and_forth") == 0 ||
+			strcasecmp(new_name, "current") == 0) {
+		free(new_name);
+		return cmd_results_new(CMD_INVALID, "rename",
+				"Cannot use special workspace name '%s'", argv[argn]);
+	}
 	struct sway_container *tmp_workspace = workspace_by_name(new_name);
 	if (tmp_workspace) {
 		free(new_name);

sway/tree/view.c

@@ -1,5 +1,6 @@
 #define _POSIX_C_SOURCE 200809L
 #include <stdlib.h>
+#include <strings.h>
 #include <wayland-server.h>
 #include <wlr/render/wlr_renderer.h>
 #include <wlr/types/wlr_buffer.h>
@@ -456,7 +457,13 @@ static struct sway_container *select_workspace(struct sway_view *view) {
 		if (criteria->type == CT_ASSIGN_WORKSPACE) {
 			ws = workspace_by_name(criteria->target);
 			if (!ws) {
-				ws = workspace_create(NULL, criteria->target);
+				if (strcasecmp(criteria->target, "back_and_forth") == 0) {
+					if (prev_workspace_name) {
+						ws = workspace_create(NULL, prev_workspace_name);
+					}
+				} else {
+					ws = workspace_create(NULL, criteria->target);
+				}
 			}
 			break;
 		} else {