Fix CloudHost Tabular Inline (#3871)

* Fix CloudHostTabularInline

* Cleanup

src/ralph/admin/templates/admin/edit_inline/tabular.html

@@ -37,7 +37,7 @@ <h2>{{ inline_admin_formset.opts.verbose_name_plural|capfirst }}</h2>
                     </td>
                   </tr>
                 {% endif %}
-                <tr class="form-row {% cycle "row1" "row2" %} {% if inline_admin_form.original or inline_admin_form.show_url %}has_original{% endif %}{% if forloop.last %} empty-form{% endif %}" id="{{ inline_admin_formset.formset.prefix }}-{% if not forloop.last %}{{ forloop.counter0 }}{% else %}empty{% endif %}">
+                <tr class="form-row {% cycle "row1" "row2" %} {% if inline_admin_form.original or inline_admin_form.show_url %}has_original{% endif %}{% if forloop.last and inline_admin_formset.has_add_permission %} empty-form{% endif %}" id="{{ inline_admin_formset.formset.prefix }}-{% if not forloop.last %}{{ forloop.counter0 }}{% else %}empty{% endif %}">
                   {% for fieldset in inline_admin_form %}
                     {% for line in fieldset %}
                       {% for field in line %}

src/ralph/virtual/admin.py

@@ -3,6 +3,7 @@
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
 from django.db.models import Count, Prefetch
+from django.forms import BaseInlineFormSet
 from django.urls import reverse
 from django.utils.safestring import mark_safe
 from django.utils.translation import ugettext_lazy as _
@@ -184,13 +185,19 @@ def parent_(self, obj):
             return '-'
 
 
+class CloudHostInlineFormset(BaseInlineFormSet):
+    def get_queryset(self):
+        return super().get_queryset()[:]
+
+
 class CloudHostTabularInline(RalphTabularInline):
     can_delete = False
     model = CloudHost
     fk_name = 'parent'
     fields = ['get_hostname', 'get_hypervisor', 'get_ip_addresses', 'created',
               'tags', 'remarks']
     readonly_fields = fields
+    formset = CloudHostInlineFormset
 
     @mark_safe
     def get_hostname(self, obj):