fix: Prevent errors when mixing keyboard/mouse input in the toolbox/flyout (#9773)

packages/blockly/core/interfaces/i_collapsible_toolbox_item.ts

@@ -42,6 +42,7 @@ export function isCollapsibleToolboxItem(
   obj: any,
 ): obj is ICollapsibleToolboxItem {
   return (
+    obj &&
     typeof obj.getChildToolboxItems === 'function' &&
     typeof obj.isExpanded === 'function' &&
     typeof obj.toggleExpanded === 'function' &&

packages/blockly/core/keyboard_nav/navigators/toolbox_navigator.ts

@@ -45,7 +45,10 @@ export class ToolboxNavigator extends Navigator {
       }
     }
 
-    if (isSelectableToolboxItem(node) && !node.getContents().length) {
+    if (
+      !isSelectableToolboxItem(node) ||
+      (isSelectableToolboxItem(node) && !node.getContents().length)
+    ) {
       return null;
     }
 

packages/blockly/core/toolbox/toolbox.ts

@@ -277,22 +277,33 @@ export class Toolbox
    * @param e Click event to handle.
    */
   protected onClick_(e: PointerEvent) {
+    const close = () => {
+      getFocusManager().focusNode(this);
+      this.clearSelection();
+      (common.getMainWorkspace() as WorkspaceSvg).hideChaff(false);
+      e.preventDefault();
+    };
+
     this.mouseDown = true;
     if (browserEvents.isRightButton(e) || e.target === this.HtmlDiv) {
       // Close flyout.
-      (common.getMainWorkspace() as WorkspaceSvg).hideChaff(false);
+      close();
     } else {
       const targetElement = e.target;
       const itemId = (targetElement as Element).getAttribute('id');
       if (itemId) {
         const item = this.getToolboxItemById(itemId);
         if (item?.isSelectable()) {
-          this.setSelectedItem(item);
           (item as ISelectableToolboxItem).onClick(e);
+          if (item === this.getSelectedItem()) {
+            close();
+          } else {
+            this.setSelectedItem(item);
+            // Just close popups.
+            (common.getMainWorkspace() as WorkspaceSvg).hideChaff(true);
+          }
         }
       }
-      // Just close popups.
-      (common.getMainWorkspace() as WorkspaceSvg).hideChaff(true);
     }
     Touch.clearTouchIdentifier();
   }

packages/blockly/tests/mocha/toolbox_test.js

@@ -234,6 +234,7 @@ suite('Toolbox', function () {
       )[0];
       const evt = {
         'target': categoryXml,
+        'stopPropagation': () => {},
       };
       const item = this.toolbox.contents.get(categoryXml.getAttribute('id'));
       const setSelectedSpy = sinon.spy(this.toolbox, 'setSelectedItem');