Cookie having a Domain cookie-attribute with empty string fails to be added to the cookie jar

Using requests to access an API hosted on an application server we noticed that cookies were not added to the cookie jar in the session.
It seems that after an upgrade to the application server framework it adds a domain=; cookie-attribute to the cookies in the response.

Expected Result

The cookie to be added to the jar

Actual Result

The cookie is dropped.

Reproduction Steps

import unittest
from typing import Tuple
from unittest.mock import MagicMock

import requests
from hamcrest import assert_that, has_length


class TestMissingSessionCookieIssue(unittest.TestCase):
    @staticmethod
    def __make_mocks(cookie_header_value: str) -> Tuple[MagicMock, MagicMock]:
        message = MagicMock()
        message.get_all.side_effect = [[], [cookie_header_value]]

        response = MagicMock()
        response.info.return_value = message

        request = MagicMock()
        request.get_full_url.return_value = "http://localhost:1234/page"
        request.origin_req_host = "localhost"

        return request, response

    def test_cookie_with_no_domain(self) -> None:
        request, response = self.__make_mocks("SESSION_ID=12345678; HttpOnly; Path=/page; SameSite=Strict")
        session = requests.session()

        session.cookies.extract_cookies(response, request)

        assert_that(session.cookies, has_length(1))

    def test_cookie_with_empty_domain(self) -> None:
        request, response = self.__make_mocks("SESSION_ID=12345678; domain=; path=/page; samesite=strict; httponly")
        session = requests.session()

        session.cookies.extract_cookies(response, request)

        assert_that(session.cookies, has_length(1))

Requirements:

• PyHamcrest==2.0.2
• requests==2.28.1
• Python 3.9

System Information

$ python -m requests.help

{
  "chardet": {
    "version": null
  },
  "charset_normalizer": {
    "version": "2.0.12"
  },
  "cryptography": {
    "version": ""
  },
  "idna": {
    "version": "3.4"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.9.5"
  },
  "platform": {
    "release": "5.14.0-1052-oem",
    "system": "Linux"
  },
  "pyOpenSSL": {
    "openssl_version": "",
    "version": null
  },
  "requests": {
    "version": "2.28.1"
  },
  "system_ssl": {
    "version": "1010106f"
  },
  "urllib3": {
    "version": "1.26.12"
  },
  "using_charset_normalizer": true,
  "using_pyopenssl": false
}

Start with the supplied TestMissingSessionCookieIssue reproduction and the session.cookies.extract_cookies entry point. Run both test methods and compare the no-domain and empty-domain cases. Done means a cookie with a domain=; attribute is added to the cookie jar, matching the expected result.