fix(runtime-dom): should properly patch as props for vue custom element (#12408)

packages/runtime-dom/__tests__/customElement.spec.ts

@@ -471,6 +471,14 @@ describe('defineCustomElement', () => {
       container.appendChild(e)
       expect(e.shadowRoot!.innerHTML).toBe('<div></div>')
     })
+
+    // #12408
+    test('should set number tabindex as attribute', () => {
+      render(h('my-el-attrs', { tabindex: 1, 'data-test': true }), container)
+      const el = container.children[0] as HTMLElement
+      expect(el.getAttribute('tabindex')).toBe('1')
+      expect(el.getAttribute('data-test')).toBe('true')
+    })
   })
 
   describe('emits', () => {

packages/runtime-dom/src/patchProp.ts

@@ -60,7 +60,11 @@ export const patchProp: DOMRendererOptions['patchProp'] = (
   } else if (
     // #11081 force set props for possible async custom element
     (el as VueElement)._isVueCE &&
-    (/[A-Z]/.test(key) || !isString(nextValue))
+    // #12408 check if it's hyphen prop or it's async custom element
+    (camelize(key) in el ||
+      // @ts-expect-error _def is private
+      ((el as VueElement)._def.__asyncLoader &&
+        (/[A-Z]/.test(key) || !isString(nextValue))))
   ) {
     patchDOMProp(el, camelize(key), nextValue, parentComponent, key)
   } else {