Only sent next parameter to login view if not empty

Setting it to "/" by default makes settings.LOGIN_REDIRECT_URL
useless, and makes the profile edit page harder to discover.

Author: bmispelon

djangoproject/templates/registration/login.html

@@ -15,7 +15,9 @@ <h1>{% translate "Log in" %}</h1>
 
     <form method="post" action="" class="form-input">
         {% csrf_token %}
-        <input type="hidden" name="next" value="{{ next|default:"/" }}">
+        {% if next %}
+            <input type="hidden" name="next" value="{{ next }}">
+        {% endif %}
 
         <div>
             <label for="id_username">{% translate "Username:" %}</label>