Ticket #20334: 20334.patch

wp-includes/theme.php

@@ -1552 +1552 @@
  */
 function check_theme_switched() {
         if ( $stylesheet = get_option( 'theme_switched' ) ) {
-                $old_theme = wp_get_theme( $stylesheet );
+                if ( $old_theme = wp_get_theme( $stylesheet ) ) {
+                        if ( $old_theme->exists() ) {
+                                do_action( 'after_switch_theme', $old_theme->get('Name'), $old_theme );
+                        } else {
+                                do_action( 'after_switch_theme', $stylesheet );
+                        }
 
-                if ( $old_theme->exists() )
-                        do_action( 'after_switch_theme', $old_theme->get('Name'), $old_theme );
-                else
-                        do_action( 'after_switch_theme', $stylesheet );
-
-                update_option( 'theme_switched', false );
+                        update_option( 'theme_switched', false );
+                }
         }
 }