Ticket #20879: 20879.2.diff

wp-includes/js/customize-base.dev.js

@@ -406 +406 @@
                                                 synchronizer = api.Element.synchronizer[ type ];
                                         if ( 'text' === type || 'password' === type )
                                                 this.events += ' keyup';
+                                } else if ( this.element.is('textarea') ) {
+                                        this.events += ' keyup';
                                 }
                         }
 

wp-admin/js/customize-controls.dev.js

@@ -573 +573 @@
 
                 // Prevent the form from saving when enter is pressed.
                 $('#customize-controls').on( 'keydown', function( e ) {
+                        if ( $( e.target ).is('textarea') )
+                                return;
+
                         if ( 13 === e.which ) // Enter
                                 e.preventDefault();
                 });