FIX Ensure files can be removed from elemental blocks

src/Controllers/ElementalAreaController.php

@@ -138,7 +138,9 @@ public function save(array $data, Form $form): HTTPResponse
         // Remove the namespace prefixes that were added by EditFormFactory
         $dataWithoutNamespaces = static::removeNamespacesFromFields($data, $element->ID);
 
-        // Update and write the data object which will trigger model validation
+        // Update and write the data object which will trigger model validation.
+        // Would usually be handled by $form->saveInto($element) but since the field names
+        // in the form have been namespaced, we need to handle it ourselves.
         $element->updateFromFormData($dataWithoutNamespaces);
         if ($element->isChanged()) {
             try {

src/Models/BaseElement.php

@@ -656,15 +656,9 @@ public function getRenderTemplates($suffix = '')
      */
     public function updateFromFormData($data)
     {
-        $cmsFields = $this->getCMSFields();
-
-        foreach ($data as $field => $datum) {
-            $field = $cmsFields->dataFieldByName($field);
-
-            if (!$field) {
-                continue;
-            }
-
+        $cmsFields = $this->getCMSFields()->saveableFields();
+        foreach ($cmsFields as $fieldName => $field) {
+            $datum = $data[$fieldName] ?? null;
             $field->setSubmittedValue($datum);
             $field->saveInto($this);
         }