From 0884588a5e2ba073c65f3e9e9ab3bf1bdb5f37d6 Mon Sep 17 00:00:00 2001
From: Tim Abbott <tabbott@zulipchat.com>
Date: Wed, 18 Oct 2017 22:46:05 -0700
Subject: [PATCH] subdomains: Add a variable for how root domain is
 represented.

We use Realm.SUBDOMAIN_FOR_ROOT_DOMAIN as the special name for how the
root domain is referred to as a subdomain in the code.
---
 zerver/lib/subdomains.py | 6 ++++--
 zerver/models.py         | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/zerver/lib/subdomains.py b/zerver/lib/subdomains.py
index 20cb651af0..4727756caa 100644
--- a/zerver/lib/subdomains.py
+++ b/zerver/lib/subdomains.py
@@ -4,19 +4,21 @@ from django.conf import settings
 from django.http import HttpRequest
 from typing import Optional, Text
 
+from zerver.models import get_realm, Realm
+
 def _extract_subdomain(request):
     # type: (HttpRequest) -> Text
     domain = request.get_host().lower()
     index = domain.find("." + settings.EXTERNAL_HOST)
     if index == -1:
-        return ""
+        return Realm.SUBDOMAIN_FOR_ROOT_DOMAIN
     return domain[0:index]
 
 def get_subdomain(request):
     # type: (HttpRequest) -> Text
     subdomain = _extract_subdomain(request)
     if subdomain in settings.ROOT_SUBDOMAIN_ALIASES:
-        return ""
+        return Realm.SUBDOMAIN_FOR_ROOT_DOMAIN
     return subdomain
 
 def is_subdomain_root_or_alias(request):
diff --git a/zerver/models.py b/zerver/models.py
index 57db99751a..3a41ad3107 100644
--- a/zerver/models.py
+++ b/zerver/models.py
@@ -137,6 +137,7 @@ class Realm(ModelReprMixin, models.Model):
     MAX_REALM_NAME_LENGTH = 40
     MAX_REALM_SUBDOMAIN_LENGTH = 40
     AUTHENTICATION_FLAGS = [u'Google', u'Email', u'GitHub', u'LDAP', u'Dev', u'RemoteUser']
+    SUBDOMAIN_FOR_ROOT_DOMAIN = ''
 
     name = models.CharField(max_length=MAX_REALM_NAME_LENGTH, null=True)  # type: Optional[Text]
     string_id = models.CharField(max_length=MAX_REALM_SUBDOMAIN_LENGTH, unique=True)  # type: Text