Redirect to login when attempting to resignup with a used email address.

(imported from commit d58a5dda9a0af409a6ee57cfcd30be45020352d2)

humbug/urls.py

@@ -14,6 +14,9 @@ urlpatterns = patterns('',
     url(r'^zephyr/', 'zephyr.views.zephyr', name='zephyr'),
     url(r'^forge_zephyr/', 'zephyr.views.forge_zephyr', name='forge_zephyr'),
     url(r'^accounts/home/', 'zephyr.views.accounts_home', name='accounts_home'),
+    # We have two entries for accounts/login to allow reverses on the Django
+    # view we're wrapping to continue to function.
+    url(r'^accounts/login/', 'zephyr.views.login_page', {'template_name': 'zephyr/login.html'}),
     url(r'^accounts/login/', 'django.contrib.auth.views.login', {'template_name': 'zephyr/login.html'}),
     url(r'^accounts/logout/', 'django.contrib.auth.views.logout', {'template_name': 'zephyr/index.html'}),
     url(r'^accounts/register/', 'zephyr.views.register', name='register'),

templates/zephyr/login.html

@@ -4,6 +4,9 @@
 
 <script type="text/javascript">
 autofocus('#id_username');
+{% if email %}
+autofocus('#id_password');
+{% endif %}
 </script>
 
     <h3>You look familiar.</h3>
@@ -14,6 +17,12 @@ autofocus('#id_username');
 </div>
 {% endif %}
 
+{% if email %}
+<div class="alert">
+    You've already registered with this email address. Please log in below.
+</div>
+{% endif %}
+
 <input type="hidden" name="next" value="{{ next }}" />
 </form>
 
@@ -22,7 +31,7 @@ autofocus('#id_username');
     <div class="control-group">
         <label for="id_username" class="control-label">Email</label>
         <div class="controls">
-            {{ form.username }}
+            <input id="id_username" type="text" name="username" value="{{ email }}" maxlength="30" />
         </div>
     </div>
     <div class="control-group">

zephyr/views.py

@@ -7,13 +7,14 @@ from django.shortcuts import render_to_response
 from django.template import RequestContext
 from django.shortcuts import render
 from django.utils.timezone import utc
-
+from django.core.exceptions import ValidationError
+from django.contrib.auth.views import login as django_login_page
 from django.contrib.auth.models import User
 from zephyr.models import Zephyr, UserProfile, ZephyrClass, Subscription, \
     Recipient, get_display_recipient, get_huddle, Realm, UserMessage, \
     create_user, do_send_zephyr, mit_sync_table, create_user_if_needed, \
     create_class_if_needed, PreregistrationUser
-from zephyr.forms import RegistrationForm, HomepageForm
+from zephyr.forms import RegistrationForm, HomepageForm, is_unique
 
 from zephyr.decorator import asynchronous
 from zephyr.lib.query import last_n
@@ -58,6 +59,11 @@ def register(request):
     email = Confirmation.objects.get(confirmation_key=key).content_object.email
     company_name = email.split('@')[-1]
 
+    try:
+        is_unique(email)
+    except ValidationError:
+        return HttpResponseRedirect(reverse('django.contrib.auth.views.login') + '?email=' + strip_html(email))
+
     try:
         dummy = request.POST['from_confirmation']
         form = RegistrationForm()
@@ -83,18 +89,32 @@ def register(request):
         'form': form, 'company_name': company_name, 'email': email, 'key': key,
     })
 
+def login_page(request, **kwargs):
+    template_response = django_login_page(request, **kwargs)
+    try:
+        template_response.context_data['email'] = strip_html(request.GET['email'])
+    except KeyError:
+        pass
+    return template_response
+
 def accounts_home(request):
     if request.method == 'POST':
         form = HomepageForm(request.POST)
         if form.is_valid():
             try:
-                user = PreregistrationUser.objects.get(email=strip_html(form.cleaned_data['email']))
+                email = form.cleaned_data['email']
+                user = PreregistrationUser.objects.get(email=email)
             except PreregistrationUser.DoesNotExist:
                 user = PreregistrationUser()
-                user.email = strip_html(form.cleaned_data['email'])
+                user.email = email
                 user.save()
             Confirmation.objects.send_confirmation(user, user.email)
             return HttpResponseRedirect(reverse('send_confirm', kwargs={'email':user.email}))
+        try:
+            email = request.POST['email']
+            is_unique(email)
+        except ValidationError:
+            return HttpResponseRedirect(reverse('django.contrib.auth.views.login') + '?email=' + strip_html(email))
     return render_to_response('zephyr/accounts_home.html',
                               context_instance=RequestContext(request))