Can not update the @ManyToMany list using PUT [DATAREST-1027]

SM opened DATAREST-1027 and commented

Hello,
if you look the simple test here below, you are able to POST @ManyToMany (groups) list but you can not update it using PUT, only the email is correctly updated:

import json

import requests

HEADERS_JSON = {'Content-Type': 'application/json'}

def printj(j):
    print(json.dumps(j, indent=4))

def test_all():
    requests.post('http://localhost:8080/groups', headers=HEADERS_JSON, data='{"name":"Admins"}')
    requests.post('http://localhost:8080/groups', headers=HEADERS_JSON, data='{"name":"Testers"}')

    rj = requests.get('http://localhost:8080/groups/').json()
    groups = rj['_embedded']['groups']

    groups_hrefs = []
    for group in groups:
        groups_hrefs.append(group['_links']['group']['href'])

    user_json = {
        "email": "fb@example.com",
        "firstName": "Frodo",
        "lastName": "Baggins",
        "groups": groups_hrefs
    }

    rj = requests.post('http://localhost:8080/users', headers=HEADERS_JSON, data=json.dumps(user_json)).json()
    user_href = rj['_links']['user']['href']

1. UPDATE

    user_json = {
        "email": "fb2@example.com",
        "firstName": "Frodo",
        "lastName": "Baggins",
        "groups": groups_hrefs[:-1]
    }

    r = requests.put(user_href, headers=HEADERS_JSON, data=json.dumps(user_json))
    print r.text


if __name__ == '__main__':
    test_all()

// Generated file
package com.github.rognoni.generated.entities;

import java.util.Date;
import java.util.List;
import javax.persistence.Entity;
import javax.persistence.Column;
import javax.persistence.ManyToMany;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name = "dry_user")
public class User {
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	private Long id;

	@Column(nullable=false)
	private String email;
	private String firstName;
	private String lastName;
	private String username;
	private String password;
	private Boolean isActive;
	private Boolean isStaff;
	private Boolean isSuperuser;
	private Date dateJoined;
	private Date lastLogin;
	@ManyToMany
	private List<Group> groups;
	@ManyToMany
	private List<Permission> permissions;

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public String getFirstName() {
		return firstName;
	}

	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}

	public String getLastName() {
		return lastName;
	}

	public void setLastName(String lastName) {
		this.lastName = lastName;
	}

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public Boolean getIsActive() {
		return isActive;
	}

	public void setIsActive(Boolean isActive) {
		this.isActive = isActive;
	}

	public Boolean getIsStaff() {
		return isStaff;
	}

	public void setIsStaff(Boolean isStaff) {
		this.isStaff = isStaff;
	}

	public Boolean getIsSuperuser() {
		return isSuperuser;
	}

	public void setIsSuperuser(Boolean isSuperuser) {
		this.isSuperuser = isSuperuser;
	}

	public Date getDateJoined() {
		return dateJoined;
	}

	public void setDateJoined(Date dateJoined) {
		this.dateJoined = dateJoined;
	}

	public Date getLastLogin() {
		return lastLogin;
	}

	public void setLastLogin(Date lastLogin) {
		this.lastLogin = lastLogin;
	}

	public List<Group> getGroups() {
		return groups;
	}

	public void setGroups(List<Group> groups) {
		this.groups = groups;
	}

	public List<Permission> getPermissions() {
		return permissions;
	}

	public void setPermissions(List<Permission> permissions) {
		this.permissions = permissions;
	}
}

No further details from DATAREST-1027