Ticket #31793: 31793.3.diff

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

@@ -1951 +1951 @@
         api.ThemeControl = api.Control.extend({
 
                 touchDrag: false,
+                isRendered: false,
 
                 /**
                  * Defer rendering the theme control until the section is displayed.
@@ -1961 +1962 @@
                         var control = this,
                                 renderContentArgs = arguments;
 
-                        api.section( control.section(), function ( section ) {
+                        api.section( control.section(), function( section ) {
                                 if ( section.expanded() ) {
                                         api.Control.prototype.renderContent.apply( control, renderContentArgs );
+                                        control.isRendered = true;
                                 } else {
-                                        section.expanded.bind( function ( expanded ) {
-                                                if ( expanded ) {
+                                        section.expanded.bind( function( expanded ) {
+                                                if ( expanded && ! control.isRendered ) {
                                                         api.Control.prototype.renderContent.apply( control, renderContentArgs );
+                                                        control.isRendered = true;
                                                 }
                                         } );
                                 }