Fixed #13883 -- Get 'add new item' function working

django/contrib/admin/options.py

@@ -69,6 +69,7 @@
 
 IS_POPUP_VAR = "_popup"
 TO_FIELD_VAR = "_to_field"
+SOURCE_MODEL_VAR = "_source_model"
 
 
 HORIZONTAL, VERTICAL = 1, 2
@@ -1296,6 +1297,7 @@ def render_change_form(
                 "save_on_top": self.save_on_top,
                 "to_field_var": TO_FIELD_VAR,
                 "is_popup_var": IS_POPUP_VAR,
+                "source_model_var": SOURCE_MODEL_VAR,
                 "app_label": app_label,
             }
         )
@@ -1341,6 +1343,16 @@ def response_add(self, request, obj, post_url_continue=None):
         # the presence of keys in request.POST.
 
         if IS_POPUP_VAR in request.POST:
+            source_model_name = request.POST.get(SOURCE_MODEL_VAR)
+            source_model = self.model._meta.app_config.get_model(source_model_name)
+            fclass = self.admin_site._registry[source_model].form
+            f = fclass()
+            choices = f.fields[self.opts.verbose_name_plural].choices
+            for optgroup, choices in choices:
+                for name, choice_obj in choices:
+                    if choice_obj == obj:
+                        obj_optgroup = optgroup
+
             to_field = request.POST.get(TO_FIELD_VAR)
             if to_field:
                 attr = str(to_field)
@@ -1351,6 +1363,7 @@ def response_add(self, request, obj, post_url_continue=None):
                 {
                     "value": str(value),
                     "obj": str(obj),
+                    "optgroup": obj_optgroup,
                 }
             )
             return TemplateResponse(
@@ -1861,6 +1874,7 @@ def _changeform_view(self, request, object_id, form_url, extra_context):
             "object_id": object_id,
             "original": obj,
             "is_popup": IS_POPUP_VAR in request.POST or IS_POPUP_VAR in request.GET,
+            "source_model": request.GET.get(SOURCE_MODEL_VAR),
             "to_field": to_field,
             "media": media,
             "inline_admin_formsets": inline_formsets,

django/contrib/admin/static/admin/js/admin/RelatedObjectLookups.js

@@ -11,15 +11,15 @@
         relatedWindows.forEach(function(win) {
             if(!win.closed) {
                 win.dismissChildPopups();
-                win.close();    
+                win.close();
             }
         });
     }
 
     function setPopupIndex() {
         if(document.getElementsByName("_popup").length > 0) {
             const index = window.name.lastIndexOf("__") + 2;
-            popupIndex = parseInt(window.name.substring(index));   
+            popupIndex = parseInt(window.name.substring(index));
         } else {
             popupIndex = 0;
         }
@@ -87,7 +87,7 @@
         }
     }
 
-    function dismissAddRelatedObjectPopup(win, newId, newRepr) {
+    function dismissAddRelatedObjectPopup(win, newId, newRepr, optgroup) {
         const name = removePopupIndex(win.name);
         const elem = document.getElementById(name);
         if (elem) {
@@ -105,8 +105,9 @@
             $(elem).trigger('change');
         } else {
             const toId = name + "_to";
-            const o = new Option(newRepr, newId);
-            SelectBox.add_to_cache(toId, o);
+            const newOption = new Option(newRepr, newId);
+            newOption.group = optgroup;
+            SelectBox.add_to_cache(toId, newOption);
             SelectBox.redisplay(toId);
         }
         const index = relatedWindows.indexOf(win);

django/contrib/admin/static/admin/js/popup_response.js

@@ -10,7 +10,7 @@
         opener.dismissDeleteRelatedObjectPopup(window, initData.value);
         break;
     default:
-        opener.dismissAddRelatedObjectPopup(window, initData.value, initData.obj);
+        opener.dismissAddRelatedObjectPopup(window, initData.value, initData.obj, initData.optgroup);
         break;
     }
 }

django/contrib/admin/templates/admin/change_form.html

@@ -37,6 +37,7 @@
 <div>
 {% if is_popup %}<input type="hidden" name="{{ is_popup_var }}" value="1">{% endif %}
 {% if to_field %}<input type="hidden" name="{{ to_field_var }}" value="{{ to_field }}">{% endif %}
+{% if source_model %}<input type="hidden" name="{{ source_model_var }}" value="{{ source_model }}">{% endif %}
 {% if save_on_top %}{% block submit_buttons_top %}{% submit_row %}{% endblock %}{% endif %}
 {% if errors %}
     <p class="errornote">

django/contrib/admin/views/main.py

@@ -11,6 +11,7 @@
 from django.contrib.admin.options import (
     IS_POPUP_VAR,
     TO_FIELD_VAR,
+    SOURCE_MODEL_VAR,
     IncorrectLookupParameters,
 )
 from django.contrib.admin.utils import (

django/contrib/admin/widgets.py

@@ -175,10 +175,13 @@ def base_url_parameters(self):
         return url_params_from_lookup_dict(limit_choices_to)
 
     def url_parameters(self):
-        from django.contrib.admin.views.main import TO_FIELD_VAR
+        from django.contrib.admin.views.main import TO_FIELD_VAR, SOURCE_MODEL_VAR
 
         params = self.base_url_parameters()
-        params.update({TO_FIELD_VAR: self.rel.get_related_field().name})
+        params.update({
+            TO_FIELD_VAR: self.rel.get_related_field().name,
+            SOURCE_MODEL_VAR: None,
+        })
         return params
 
     def label_and_url_for_value(self, value):
@@ -295,17 +298,19 @@ def get_related_url(self, info, action, *args):
         )
 
     def get_context(self, name, value, attrs):
-        from django.contrib.admin.views.main import IS_POPUP_VAR, TO_FIELD_VAR
+        from django.contrib.admin.views.main import IS_POPUP_VAR, TO_FIELD_VAR, SOURCE_MODEL_VAR
 
         rel_opts = self.rel.model._meta
         info = (rel_opts.app_label, rel_opts.model_name)
         self.widget.choices = self.choices
         related_field_name = self.rel.get_related_field().name
+        m = self.rel.field.model
         url_params = "&".join(
             "%s=%s" % param
             for param in [
                 (TO_FIELD_VAR, related_field_name),
                 (IS_POPUP_VAR, 1),
+                (SOURCE_MODEL_VAR, m.__name__),
             ]
         )
         context = {