net/ghttp: The new version of nested field parsing is invalid

[shuqingzai]

Go version

go version go1.21.13 darwin/amd64

GoFrame version

2.7.3

Can this bug be reproduced with the latest release?

Option Yes

What did you do?

在 2.7.2 以下代码运行正常，但是 2.7.3 解析请求参数错误

config.yaml

server:
  address:     ":8199"
  openapiPath: "/api.json"
  swaggerPath: "/swagger"

main.go

package main

import (
	"context"

	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/net/ghttp"
)

type ItemInput struct {
	ItemFirst
}

type ItemSecondThird struct {
	// SecondID ...
	SecondID uint64 `json:"secondId,string" dc:"SecondID" v:"required"`
	// ThirdID ...
	ThirdID uint64 `json:"thirdId,string" dc:"ThirdID" v:"required"`
}

type ItemFirst struct {
	// ID ID
	ID uint64 `json:"id,string" dc:"ID"`

	ItemSecondThird
}

type HelloReq struct {
	g.Meta `path:"/hello" method:"GET"`

	ItemInput
}
type HelloRes struct {
	ItemInput
}

type Hello struct{}

func (Hello) Say(ctx context.Context, req *HelloReq) (res *HelloRes, err error) {
	g.Log().Debugf(ctx, `receive say: %+v`, req)
	res = &HelloRes{
		ItemInput: req.ItemInput,
	}
	return
}

func main() {
	s := g.Server()
	s.Use(ghttp.MiddlewareHandlerResponse)
	s.Group("/", func(group *ghttp.RouterGroup) {
		group.Bind(
			new(Hello),
		)
	})
	s.Run()
}

What did you see happen?

分别使用不同版本启动服务，得到不同的响应结果

使用请求

curl -X GET 'http://127.0.0.1:8199/hello?id=&secondId=157889372459384832&thirdId=157889372459384833' \
-H 'Host: 127.0.0.1:8199'

1. 2.7.2

正确解析请求参数 secondId

{"code":0,"message":"","data":{"id":"0","secondId":"157889372459384832","thirdId":"157889372459384833"}}

3. 2.7.3

没有正确解析请求参数 secondId ，甚至说试多几次，有时候 thirdId 的值会被赋值到 secondId ，值被缓存？？

{"code":0,"message":"","data":{"id":"0","secondId":"0","thirdId":"157889372459384833"}}

What did you expect to see?

参数被正确解析

[wln32]

@shuqingzai @gqcn
目前已经找到原因了，竟是slice扩容机制导致的，这个bug非常有意思

下面是我打印不同字段的切片的详细信息
可以看到最后两个字段，切片的地址是相同的，在before的时候，也就是调用structInfo.AddField之前，由于len<cap，
SecondID扩容之后变成[1 0 1 0]，由于ThirdID和SecondID的引用的相同的地址，ThirdID扩容切片会变成[1 0 1 1]，
覆盖了SecondID的索引信息，导致参数解析失败

@shuqingzai 如果对2.7.3没有特别需求，暂时退到2.7.2版本

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---

@shuqingzai @gqcn The real reason has been found so far. It is actually caused by the slice expansion mechanism. This bug is very interesting! [image](https://private-user-images.githubusercontent.com/49137144/369721902-3d6cb923-473d -4955-8a86-7c1276e64547.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..B7wWhBcWgWKUIlPoO0_AsBflR8q8hSqo83Fis5mP1ec)

Below is the detailed information of the slices I printed with different fields. You can see the last two fields. The addresses of the slices are the same. Before, that is, before calling structInfo.AddField, because len<cap, SecondID becomes [1 0 1 0], since ThirdID and SecondID refer to the same address, the expansion of ThirdID will slice it into [1 0 1 1], covering the index information of SecondID, causing parameter parsing to fail! [image](https: //private-user-images.githubusercontent.com/49137144/369721747-6325acd7-f880-48e6-ae6a-be834d983041.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..1iayo14olicpDtuLhPQ8 162UqscD2aXvQaGLPnbXEOc)

@shuqingzai If there is no special need for 2.7.3, we will temporarily fall back to version 2.7.2