Ticket #39537: 39537.diff

src/wp-includes/theme.php

@@ -737 +737 @@
                                 set_theme_mod( 'nav_menu_locations', $nav_menu_locations );
                         }
                 }
+
+                $autoload_options = wp_cache_get( 'alloptions', 'options' );
+                if ( ! is_array( $autoload_options ) ) {
+                        $autoload_options = array();
+                }
+
+                if ( ! in_array( "theme_mods_$stylesheet", $autoload_options ) ) {
+                        // If the switched theme options are not autoload, update to autoload=yes
+                        $theme_mods = get_option( "theme_mods_$stylesheet" );
+                        delete_option( "theme_mods_$stylesheet" );
+                        add_option( "theme_mods_$stylesheet", $theme_mods );
+                }
         }
 
         update_option( 'theme_switched', $old_theme->get_stylesheet() );
 
+        // Set autoload=no for the previous theme (delete and add the option again is needed for this purpose)
+        $old_theme_stylesheet = $old_theme->get_stylesheet();
+        $old_theme_mods = get_option( "theme_mods_$old_theme_stylesheet" );
+        delete_option( "theme_mods_$old_theme_stylesheet" );
+        add_option( "theme_mods_$old_theme_stylesheet", $old_theme_mods, null, 'no' );
+
+        // Reload autoload options
+        wp_load_alloptions();
+
         /**
          * Fires after the theme is switched.
          *