Fix support for having a unique, open realm.

The previous implementation didn't work because HomepageForm rejected
the email as not having a domain.  Additionally, the logic in
accounts_register didn't work with Google auth because that code path
doesn't pass through accounts_home.  Since whether there's a unique
open realm for the server is effectively a configuration property, we
can fix the bug and make the logic clearer by moving it into the
"figure out the user's realm" function.

zerver/forms.py

@@ -7,7 +7,7 @@ from django.contrib.auth.forms import SetPasswordForm, AuthenticationForm
 from django.conf import settings
 
 from zerver.models import Realm, get_user_profile_by_email, UserProfile, \
-    completely_open, resolve_email_to_domain, get_realm
+    completely_open, resolve_email_to_domain, get_realm, get_unique_open_realm
 from zerver.lib.actions import do_change_password, is_inactive
 from zproject.backends import password_auth_enabled
 import DNS
@@ -69,7 +69,9 @@ class HomepageForm(forms.Form):
 
     def clean_email(self):
         data = self.cleaned_data['email']
-        if completely_open(self.domain) or has_valid_realm(data) and not_mit_mailing_list(data):
+        if (get_unique_open_realm() or
+            completely_open(self.domain) or
+            (has_valid_realm(data) and not_mit_mailing_list(data))):
             return data
         raise ValidationError(mark_safe(SIGNUP_STRING))
 

zerver/views/__init__.py

@@ -85,11 +85,16 @@ def accounts_register(request):
         existing_user_profile = None
 
     validators.validate_email(email)
+
+    unique_open_realm = get_unique_open_realm()
+    if unique_open_realm:
+        realm = unique_open_realm
+        domain = realm.domain
+    elif not mit_beta_user and prereg_user.referred_by:
         # If someone invited you, you are joining their realm regardless
         # of your e-mail address.
         #
         # MitUsers can't be referred and don't have a referred_by field.
-    if not mit_beta_user and prereg_user.referred_by:
         realm = prereg_user.referred_by.realm
         domain = realm.domain
         if realm.restricted_to_domain and domain != resolve_email_to_domain(email):
@@ -99,10 +104,11 @@ def accounts_register(request):
         # happens if you sign up through a special URL for an open
         # realm.
         domain = prereg_user.realm.domain
+        realm = get_realm(domain)
     else:
         domain = resolve_email_to_domain(email)
-
         realm = get_realm(domain)
+
     if realm and realm.deactivated:
         # The user is trying to register for a deactivated realm. Advise them to
         # contact support.
@@ -635,13 +641,6 @@ def send_registration_completion_email(email, request):
                                            additional_context=context)
 
 def accounts_home(request):
-    # First we populate request.session with a domain if
-    # there is a single realm, which is open.
-    # This is then used in HomepageForm and in creating a PreregistrationUser
-    unique_realm = get_unique_open_realm()
-    if unique_realm:
-        request.session['domain'] = unique_realm.domain
-
     if request.method == 'POST':
         form = create_homepage_form(request, user_info=request.POST)
         if form.is_valid():