Ticket #44151: 44151.2.patch

wp-admin/includes/file.php

@@ -2347 +2347 @@
                         $groups[ $group_id ]['items'][ $item_id ] = array();
                 }
 
-                $old_item_data = $groups[ $group_id ]['items'][ $item_id ];
-                $merged_item_data = array_merge( $export_datum['data'], $old_item_data );
+                $merged_item_data = $groups[ $group_id ]['items'][ $item_id ];
+                //append the new data, but don't overwrite the data that has already been collected
+                foreach ( $export_datum['data'] as $new_key => $new_value ) {
+                        if ( is_int( $new_key ) ) {
+                                //append numeric indices, similar to the array_merge functionality
+                                $merged_item_data[] = $new_value;
+                                continue;
+                        }
+
+                        if ( array_key_exists( $new_key, $merged_item_data ) ) {
+                                //avoid overwriting the existing higher priority data with lower priority
+                                continue;
+                        }
+
+                        $merged_item_data[ $new_key ] = $new_value;
+                }
+
                 $groups[ $group_id ]['items'][ $item_id ] = $merged_item_data;
         }