Fix regression in RTA: heading with a single level does not work

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## Changes
 
+1.5.3
+  * Fix: Regression in `RichtextArea`, heading with a single level does not work.
+
 1.5.2
   * Fix naming issue in interactive docs, preventing the dialog not to close.
   * Fix in RichtextArea: Dropdown menu did not show up at the right position.

client/django-formset/RichtextArea.ts

@@ -580,7 +580,14 @@ namespace controls {
 		protected toggleItem(event: MouseEvent, editor: Editor) {
 			let element = event.target instanceof Element ? event.target : null;
 			while (element) {
-				if (element.role === 'menuitem') {
+				if (this.dropdownItems.length === 0) {
+					if (element === this.button) {
+						const level = this.extractLevel(element);
+						editor.chain().focus().setHeading({level: level}).run();
+						this.activate(editor);
+						break;
+					}
+				} else if (element.role === 'menuitem') {
 					const level = this.extractLevel(element);
 					editor.chain().focus().setHeading({level: level}).run();
 					this.activate(editor);