user: replace MarshalJSON with a legacy field

MarshalJSON causes side effect when use *User as embeded struct gogs/gogs#5538.

Author: unknwon

gogs.go

@@ -14,7 +14,7 @@ import (
 )
 
 func Version() string {
-return "0.12.13"
+return "0.12.14"
 }
 
 // Client represents a Gogs API client.

user.go

@@ -5,30 +5,19 @@
 package gogs
 
 import (
-"encoding/json"
 "fmt"
 )
 
 // User represents a API user.
 type User struct {
 ID int64 `json:"id"`
-UserName string `json:"login"`
+UserName string `json:"username"` // LEGACY [Gogs 1.0]: remove field(s) for backward compatibility
+Login string `json:"login"`
 FullName string `json:"full_name"`
 Email string `json:"email"`
 AvatarUrl string `json:"avatar_url"`
 }
 
-// MarshalJSON implements the json.Marshaler interface for User
-func (u User) MarshalJSON() ([]byte, error) {
-// Re-declaring User to avoid recursion
-type shadow User
-return json.Marshal(struct {
-shadow
-// LEGACY [Gogs 1.0]: remove field(s) for backward compatibility
-CompatUserName string `json:"username"`
-}{shadow(u), u.UserName})
-}
-
 func (c *Client) GetUserInfo(user string) (*User, error) {
 u := new(User)
 err := c.getParsedResponse("GET", fmt.Sprintf("/users/%s", user), nil, nil, u)