bpo-25068: urllib.request.ProxyHandler now lowercases the dict keys (GH-13489)

(cherry picked from commit b761e3aed1)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Lib/test/test_urllib2.py

@@ -1340,8 +1340,10 @@ class HandlerTests(unittest.TestCase):
                 self.assertTrue(request.startswith(expected), repr(request))
 
     def test_proxy(self):
+        u = "proxy.example.com:3128"
+        for d in dict(http=u), dict(HTTP=u):
             o = OpenerDirector()
-        ph = urllib.request.ProxyHandler(dict(http="proxy.example.com:3128"))
+            ph = urllib.request.ProxyHandler(d)
             o.add_handler(ph)
             meth_spec = [
                 [("http_open", "return response")]
@@ -1351,8 +1353,7 @@ class HandlerTests(unittest.TestCase):
             req = Request("http://acme.example.com/")
             self.assertEqual(req.host, "acme.example.com")
             o.open(req)
-        self.assertEqual(req.host, "proxy.example.com:3128")
-
+            self.assertEqual(req.host, u)
             self.assertEqual([(handlers[0], "http_open")],
                              [tup[0:2] for tup in o.calls])
 

Lib/urllib/request.py

@@ -800,6 +800,7 @@ class ProxyHandler(BaseHandler):
         assert hasattr(proxies, 'keys'), "proxies must be a mapping"
         self.proxies = proxies
         for type, url in proxies.items():
+            type = type.lower()
             setattr(self, '%s_open' % type,
                     lambda r, proxy=url, type=type, meth=self.proxy_open:
                         meth(r, proxy, type))

Misc/NEWS.d/next/Library/2019-05-22-04-52-35.bpo-25068.vR_rC-.rst

@@ -0,0 +1,2 @@
+:class:`urllib.request.ProxyHandler` now lowercases the keys of the passed
+dictionary.