Widgets: Allow basic inline tags in `wp_sidebar_description()`.

The customizer has allowed HTML in sidebar descriptions since adding support for sidebars. This change ensures that basic HTML is also allowed for them in the widgets admin screen.

Fixes #42608.

Built from https://develop.svn.wordpress.org/trunk@43275


git-svn-id: http://core.svn.wordpress.org/trunk@43104 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43274';
+$wp_version = '5.0-alpha-43275';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-includes/widgets.php

@@ -426,7 +426,7 @@ function wp_sidebar_description( $id ) {
 	global $wp_registered_sidebars;
 
 	if ( isset( $wp_registered_sidebars[ $id ]['description'] ) ) {
-		return esc_html( $wp_registered_sidebars[ $id ]['description'] );
+		return wp_kses( $wp_registered_sidebars[ $id ]['description'], 'sidebar_description' );
 	}
 }