Fix bug in dev login which showed email/password prompts on logins after the first.

(imported from commit 626684ef1da8feb53aca05c9225ee628156f9810)

zerver/context_processors.py

@@ -5,10 +5,7 @@ import ujson
 from zproject.backends import password_auth_enabled, dev_auth_enabled, google_auth_enabled
 
 def add_settings(request):
-    if hasattr(request.user, "realm"):
-        is_pw_auth_enabled = password_auth_enabled(request.user.realm)
-    else:
-        is_pw_auth_enabled = True
+    realm = request.user.realm if hasattr(request.user, "realm") else None
     return {
         'full_navbar':   settings.FULL_NAVBAR,
         # We use the not_enterprise variable name so that templates
@@ -24,7 +21,7 @@ def add_settings(request):
         'api_site_required': settings.EXTERNAL_API_PATH != "api.zulip.com",
         'email_integration_enabled': settings.EMAIL_GATEWAY_BOT != "",
         'email_gateway_example': settings.EMAIL_GATEWAY_EXAMPLE,
-        'password_auth_enabled': is_pw_auth_enabled,
+        'password_auth_enabled': password_auth_enabled(realm),
         'dev_auth_enabled': dev_auth_enabled(),
         'google_auth_enabled': google_auth_enabled(),
     }

zproject/backends.py

@@ -14,6 +14,7 @@ from apiclient.sample_tools import client as googleapiclient
 from oauth2client.crypt import AppIdentityError
 
 def password_auth_enabled(realm):
+    if realm is not None:
         if realm.domain == 'employees.customer16.invalid':
             return False
         elif realm.domain == 'zulip.com' and settings.DEPLOYED: