fix(): Avoid firing twice in subselection

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [next]
 
+- fix(Canvas): avoid firing event twice when working with nested objects [#9329](https://github.com/fabricjs/fabric.js/pull/9329)
 - fix(Control): `calcCornerCoords` angle + calculation [#9377](https://github.com/fabricjs/fabric.js/pull/9377)
 - patch(): dep findCrossPoints in favor of `isPointInPolygon` [#9374](https://github.com/fabricjs/fabric.js/pull/9374)
 - docs() enable typedocs to run again [#9356](https://github.com/fabricjs/fabric.js/pull/9356)

src/canvas/Canvas.ts

@@ -903,7 +903,7 @@ export class Canvas extends SelectableCanvas implements CanvasOptions {
     this.fire(eventType, options);
     target && target.fire(eventType, options);
     for (let i = 0; i < subTargets.length; i++) {
-      subTargets[i].fire(eventType, options);
+      subTargets[i] !== target && subTargets[i].fire(eventType, options);
     }
     return options;
   }
@@ -943,7 +943,7 @@ export class Canvas extends SelectableCanvas implements CanvasOptions {
     // this may be a little be more complicated of what we want to handle
     target && target.fire(`mouse${eventType}`, options);
     for (let i = 0; i < targets.length; i++) {
-      targets[i].fire(`mouse${eventType}`, options);
+      targets[i] !== target && targets[i].fire(`mouse${eventType}`, options);
     }
   }
 

src/canvas/__tests__/eventData.test.ts

@@ -1,7 +1,10 @@
 /* eslint-disable no-restricted-globals */
 import '../../../jest.extend';
+import type { TPointerEvent } from '../../EventTypeDefs';
 import { Point } from '../../Point';
+import { Group } from '../../shapes/Group';
 import { IText } from '../../shapes/IText/IText';
+import { FabricObject } from '../../shapes/Object/FabricObject';
 import type { TMat2D } from '../../typedefs';
 import { Canvas } from '../Canvas';
 
@@ -100,3 +103,22 @@ describe('Canvas event data', () => {
     }
   );
 });
+
+it('A selected subtarget should not fire an event twice', () => {
+  const target = new FabricObject();
+  const group = new Group([target], {
+    subTargetCheck: true,
+    interactive: true,
+  });
+  const canvas = new Canvas(null);
+  canvas.add(group);
+  const targetSpy = jest.fn();
+  target.on('mousedown', targetSpy);
+  jest.spyOn(canvas, '_checkTarget').mockReturnValue(true);
+  canvas.__onMouseDown({
+    target: canvas.getSelectionElement(),
+    clientX: 0,
+    clientY: 0,
+  } as unknown as TPointerEvent);
+  expect(targetSpy).toHaveBeenCalledTimes(1);
+});