Loop variable defined in for loop in template becomes undefined

[silane]

Vue version

3.3.4

Link to minimal reproduction

https://play.vuejs.org/#eNqNUsFu2zAM/RVBGOAUSOxDd8qSIOvQw3bYhm23aQfHphO3tiRQdOKi8L+PkhLPy4aiJ4nkI9/jk57le2vTYwdyKVeuwNrSRum6tQZJPAuESgyiQtOKhEHJO6WVhj5US6jyrmGU0kI4oM7ObmIgRGG0I5Ej5k9i7afMfiaVMclcJLsck183PMjjqk4XVBst3MGcZv3YL0TeABJnzsAhHsg0qFlYGD0PbWIImGGutL+tsnENDgha2+QEHK12HRFT0ZOFtZIxUlJsi6YuHjnzBo6gSaw3UcV5B9YfyAJJkJl7UT6qDM4iqhemirBxhfNGURtLU3JzFyhXWaT2krKJPjmX5HhcVe/TB2c0v0gYpWRhWluzH1+s98opubyQKJk3jTl9CjnCDtiEmC8OUDz+J//gep9T8iuCAzyCkmONctwDxfL998/Q830stqbsGka/UPwGzjSd1xhhd50uWfYEF9R+DL+r1vsf7r4n0O6ylBd6eUqP5h/34YXV/8i9TW8vNrOL8fcu2txe+RgLfw9hjij2QGTdMsuKUnNbCU19xFQDZdq22ZZhGXaa6hYWpWm3zJi+zcra0TSdgmsXOzQndpaHTBb3/cFuXCDoEtDb8jraq7Yp9VXpH/rRlOE31PdOXQ==

Steps to reproduce

Open reproduction link and click the button.

What is expected?

Alerts should display foo,bar, foo and bar in sequence.

What is actually happening?

Alerts display foo,bar, undefined and undefined in sequence, which means the loop variable x becomes undefined while the normal variable a is fine.

System Info

No response

Any additional comments?

No response

[edison1105]

duplicate of #7238