Ticket #39085: 39085.0.diff

src/wp-includes/class-wp-customize-manager.php

@@ -4128 +4128 @@
                         'type'     => 'textarea',
                         'section'  => 'custom_css',
                         'settings' => array( 'default' => $custom_css_setting->id ),
+                        'input_attrs' => array(
+                                'dir' => 'ltr',
+                        ),
                 ) );
         }