add form:"-" to ignore bind is not working

[hotcoffie]

its not working properly now. When I added form:"-" to my field, the field is still being assigned a value regardless of whether I use Bind or ShouldBind.

go 1.21 github.com/gin-gonic/gin v1.9.1

type Astruct struct {
	Aa string  `form:"-" json:"aa"`
	Bb *string `form:"-" json:"bb"`
}

func Init(r *gin.Engine) {

	api := r.Group("/api")
	{
		api.GET("/ping", func(c *gin.Context) {
			c.JSON(http.StatusOK, "pong")
		})

		api.POST("/test", func(ctx *gin.Context) {
			var a Astruct
			ctx.Bind(&a)
			fmt.Println(a.Aa)
			fmt.Println(*a.Bb)
			ctx.AbortWithStatus(http.StatusOK)
		})
	}
}

POST http://127.0.0.1:9527/api/test
Content-Type: application/json

{
	"aa": "a",
	"bb": "b"
}

a
b
2023-09-05T01:30:16.577+0800	DEBUG	utils/logger.go:43	gin	{"method": "POST", "path": "/api/test", "status": 200, "ip": "127.0.0.1", "elapsed": "243.845µs"}

Originally posted by @hotcoffie in https://github.com/gin-gonic/gin/issues/1733#issuecomment-1705569584