Fixed #16919 -- Passed user to set_password_form in GET requests.

Thanks Jaime Irurzun for the report and initial patch and
ejucovy for the test.

django/contrib/auth/tests/templates/registration/password_reset_confirm.html

@@ -1,5 +1,7 @@
+Hello, {{ form.user }}.
+
 {% if validlink %}
 Please enter your new password: {{ form }}
 {% else %}
 The password reset link was invalid
-{% endif %}
+{% endif %}

django/contrib/auth/tests/test_views.py

@@ -307,6 +307,22 @@ class PasswordResetTest(AuthViewsTestCase):
         self.assertEqual(response.status_code, 302)
         self.assertURLEqual(response.url, '/password_reset/')
 
+    def test_confirm_display_user_from_form(self):
+        url, path = self._test_confirm_start()
+        response = self.client.get(path)
+
+        # #16919 -- The ``password_reset_confirm`` view should pass the user
+        # object to the ``SetPasswordForm``, even on GET requests.
+        # For this test, we render ``{{ form.user }}`` in the template
+        # ``registration/password_reset_confirm.html`` so that we can test this.
+        username = User.objects.get(email='staffmember@example.com').username
+        self.assertContains(response, "Hello, %s." % username)
+
+        # However, the view should NOT pass any user object on a form if the
+        # password reset link was invalid.
+        response = self.client.get('/reset/zzzzzzzzzzzzz/1-1/')
+        self.assertContains(response, "Hello, .")
+
 
 @override_settings(AUTH_USER_MODEL='auth.CustomUser')
 class CustomUserPasswordResetTest(AuthViewsTestCase):

django/contrib/auth/views.py

@@ -216,7 +216,7 @@ def password_reset_confirm(request, uidb64=None, token=None,
                 form.save()
                 return HttpResponseRedirect(post_reset_redirect)
         else:
-            form = set_password_form(None)
+            form = set_password_form(user)
     else:
         validlink = False
         form = None