Swag init fails for recursive cyclic references involving embedded structs

[takanuva15]

Describe the bug
When there are 2 "child" structs that embed the same struct S1, and S1 also has a pointer to one of the child structs, swag init is unable to parse it and errors out.

To Reproduce
Steps to reproduce the behavior:

1. Create a new go file with the following MVE using the gin framework:

main.go

package main

import (
	"net/http"

	"github.com/gin-gonic/gin"
)

type Parent struct {
	Child2 *Child2
}

type Child1 struct {
	Parent
	Prop1 string
}
type Child2 struct {
	Parent
	Prop2 string
}

func main() {
	r := gin.Default()
	r.GET("/ping", Get)
	_ = r.Run() // listen and serve on 0.0.0.0:8080 (for windows "localhost:8080")
}

// Get
// @Success      200  {object}  Child1
// @Router       /ping [get]
func Get(c *gin.Context) {
	c2 := Child2{Prop2: "c2"}
	c1 := Child1{Prop1: "c1", Parent: Parent{Child2: &c2}}
	c.JSON(http.StatusOK, c1)
}

The go.mod file can be generated as:

go mod init dummy
go get github.com/gin-gonic/gin

2. Run swag init
3. Note that the following error gets printed:

swag init
2024/12/09 16:58:59 Generate swagger docs....
2024/12/09 16:58:59 Generate general API Info, search dir:./
2024/12/09 16:59:00 Generating main.Child1
2024/12/09 16:59:00 Generating main.Parent
2024/12/09 16:59:00 Generating main.Child2
2024/12/09 16:59:00 Skipping 'main.Parent', recursion detected.
2024/12/09 16:59:00 Error parsing type definition 'main.Child2': Parent: recursively parsing struct
2024/12/09 16:59:00 Error parsing type definition 'main.Parent': [child2]: Child2: Parent: recursively parsing struct
2024/12/09 16:59:00 Error parsing type definition 'main.Child1': Parent: [child2]: Child2: Parent: recursively parsing struct
2024/12/09 16:59:00 ParseComment error in file /Users/takanuva15/Documents/Repositories/dummy/main.go :Child1: Parent: [child2]: Child2: Parent: recursively parsing struct

4. Now run the actual gin server via go run main.go
5. curl 'http://localhost:8080/ping'
6. Note that the output works perfectly fine:

{
    "Child2": {
        "Child2": null,
        "Prop2": "c2"
    },
    "Prop1": "c1"
}

Expected behavior
The swag init should generate docs normally using definition references as it already does for normal cyclic references

Screenshots
N/A

Your swag version
1.16.4

Your go version
1.23.3

Desktop (please complete the following information):

• OS: macOS
• Browser: Chrome 131.0.6778.109
• Version: Sonoma 14.7.1

Additional context
This example has been boiled down for simplicity, but we do have places in the actual Golang model we use in our company where 2 child structs embed the same parent struct, yet the parent struct has a pointer to one of the child structs as well. (It's not great, but we cannot get rid of it since it would break our existing production environment)