Update name after value has been saved

Author: wilr

src/ManyField.php

@@ -601,10 +601,6 @@ public function FieldList() {
     protected function updateManyNestedField($field, $index, $value, $prefixName) {
         $name = $field->name;
 
-        if ($prefixName) {
-            $field->name = $this->name . '['.$field->name . ']['. $index . ']';
-        }
-
         if ($field instanceof CompositeField) {
             foreach ($field->getChildren() as $c) {
                 $c = $this->updateManyNestedField($c, $index, $value, false);
@@ -623,6 +619,10 @@ protected function updateManyNestedField($field, $index, $value, $prefixName) {
             } else {
                 $field->setValue($value);
             }
+
+            if ($prefixName) {
+                $field->name = $this->name . '['.$field->name . ']['. $index . ']';
+            }
         }
 
         if (isset($this->fieldCallbacks[$name])) {