Fix handling of zero and empty cookie values in RequestsCookieJar

src/requests/cookies.py

@@ -395,22 +395,22 @@ def _find_no_duplicates(self, name, domain=None, path=None):
             that match name and optionally domain and path
         :return: cookie.value
         """
-        toReturn = None
+        foundCookie = None
         for cookie in iter(self):
             if cookie.name == name:
                 if domain is None or cookie.domain == domain:
                     if path is None or cookie.path == path:
-                        if toReturn is not None:
+                        if foundCookie is not None:
                             # if there are multiple cookies that meet passed in criteria
                             raise CookieConflictError(
                                 f"There are multiple cookies with name, {name!r}"
                             )
                         # we will eventually return this as long as no cookie conflict
-                        toReturn = cookie.value
+                        foundCookie = cookie
 
-        if toReturn:
-            return toReturn
-        raise KeyError(f"name={name!r}, domain={domain!r}, path={path!r}")
+        if foundCookie is None:
+            raise KeyError(f"name={name!r}, domain={domain!r}, path={path!r}")
+        return foundCookie.value
 
     def __getstate__(self):
         """Unlike a normal CookieJar, this class is pickleable."""

tests/test_cookies.py

@@ -0,0 +1,62 @@
+from my_requests.cookies import RequestsCookieJar
+
+
+def test_cookie_empty_value_bug():
+    jar = RequestsCookieJar()
+    jar.set('token', 0, domain='example.com', path='/')
+
+    assert list(jar.items()) == [('token', 0)]
+    assert jar.get('token', domain='example.com', path='/') == 0
+
+
+def test_cookie_zero_value_among_others():
+    jar = RequestsCookieJar()
+    jar.set('token', 0, domain='example.com', path='/')
+    jar.set('session', 'abc', domain='example.com', path='/')
+
+    assert jar.get('token', domain='example.com', path='/') == 0
+
+
+def test_cookie_string_zero_value():
+    jar = RequestsCookieJar()
+    jar.set('code', '0', domain='example.com', path='/')
+
+    assert jar.get('code', domain='example.com', path='/') == '0'
+
+
+def test_cookie_empty_string_value():
+    jar = RequestsCookieJar()
+    jar.set('empty', '', domain='example.com', path='/')
+
+    assert jar.get('empty', domain='example.com', path='/') == ''
+
+
+def test_cookie_none_value():
+    jar = RequestsCookieJar()
+    jar.set('missing', None, domain='example.com', path='/')
+
+    assert jar.get('missing', domain='example.com', path='/') is None
+
+
+def test_cookie_zero_value_with_domain_and_path_matching():
+    jar = RequestsCookieJar()
+    jar.set('token', 0, domain='example.com', path='/api')
+
+    assert jar.get('token', domain='example.com', path='/api') == 0
+
+
+def test_cookie_overwrite_zero_value():
+    jar = RequestsCookieJar()
+    jar.set('token', 'old', domain='example.com', path='/')
+    jar.set('token', 0, domain='example.com', path='/')
+
+    assert jar.get('token', domain='example.com', path='/') == 0
+
+
+def test_cookie_zero_value_persists_after_update():
+    jar = RequestsCookieJar()
+    jar.set('token', 0, domain='example.com', path='/')
+
+    jar.update(jar)
+
+    assert jar.get('token', domain='example.com', path='/') == 0