Fixes #3999: Do not filter child results by null if non-required parent fields are blank

docs/release-notes/version-2.7.md

@@ -9,6 +9,7 @@
 
 * [#3983](https://github.com/netbox-community/netbox/issues/3983) - Permit the creation of multiple unnamed devices
 * [#3989](https://github.com/netbox-community/netbox/issues/3989) - Correct HTTP content type assignment for webhooks
+* [#3999](https://github.com/netbox-community/netbox/issues/3999) - Do not filter child results by null if non-required parent fields are blank
 
 ---
 

netbox/project-static/js/forms.js

@@ -158,14 +158,17 @@ $(document).ready(function() {
 
                 filter_for_elements.each(function(index, filter_for_element) {
                     var param_name = $(filter_for_element).attr(attr_name);
+                    var is_required = $(filter_for_element).attr("required");
                     var is_nullable = $(filter_for_element).attr("nullable");
                     var is_visible = $(filter_for_element).is(":visible");
                     var value = $(filter_for_element).val();
 
-                    if (param_name && is_visible && value) {
-                        parameters[param_name] = value;
-                    } else if (param_name && is_visible && is_nullable) {
-                        parameters[param_name] = "null";
+                    if (param_name && is_visible) {
+                        if (value) {
+                            parameters[param_name] = value;
+                        } else if (is_required && is_nullable) {
+                            parameters[param_name] = "null";
+                        }
                     }
                 });