Add case_insensitive option to Cookie.has_nonstandard_attr method

Cookie.has_nonstandard_attr method is case-sensitive, but HTTP is
case-insensitive for cookie attribute names. This option is useful
for MozillaCookieJar to check the HttpOnly flag when saving.

Author: kairi003

Doc/library/http.cookiejar.rst

@@ -716,9 +716,10 @@ Cookies may have additional non-standard cookie-attributes.  These may be
 accessed using the following methods:
 
 
-.. method:: Cookie.has_nonstandard_attr(name)
+.. method:: Cookie.has_nonstandard_attr(name, case_insensitive=False)
 
-   Return ``True`` if cookie has the named cookie-attribute.
+   Return ``True`` if cookie has the named cookie-attribute. If *case_insensitive*
+   is true, the name is compared without regard to case.
 
 
 .. method:: Cookie.get_nonstandard_attr(name, default=None)

Lib/http/cookiejar.py

@@ -800,7 +800,10 @@ def __init__(self, version, name, value,
 
         self._rest = copy.copy(rest)
 
-    def has_nonstandard_attr(self, name):
+    def has_nonstandard_attr(self, name, case_insensitive=False):
+        if case_insensitive:
+            name = name.lower()
+            return any(k.lower() == name for k in self._rest)
         return name in self._rest
     def get_nonstandard_attr(self, name, default=None):
         return self._rest.get(name, default)

Lib/test/test_http_cookiejar.py

@@ -623,6 +623,7 @@ def test_ns_parser(self):
         # case is preserved
         self.assertTrue(cookie.has_nonstandard_attr("blArgh"))
         self.assertFalse(cookie.has_nonstandard_attr("blargh"))
+        self.assertTrue(cookie.has_nonstandard_attr("blargh", case_insensitive=True))
 
         cookie = c._cookies["www.acme.com"]["/"]["ni"]
         self.assertEqual(cookie.domain, "www.acme.com")