Ticket #36952: 36952.2.diff

src/wp-includes/class-wp-customize-setting.php

@@ -587 +587 @@
                 $id_base = $this->id_data['base'];
                 if ( 'option' === $this->type ) {
                         return get_option( $id_base, $default );
-                } else if ( 'theme_mod' ) {
+                } elseif ( 'theme_mod' === $this->type ) {
                         return get_theme_mod( $id_base, $default );
                 } else {
                         /*
@@ -616 +616 @@
                                 $autoload = self::$aggregated_multidimensionals[ $this->type ][ $this->id_data['base'] ]['autoload'];
                         }
                         return update_option( $id_base, $value, $autoload );
-                } else if ( 'theme_mod' ) {
+                } elseif ( 'theme_mod' === $this->type ) {
                         set_theme_mod( $id_base, $value );
                         return true;
                 } else {

tests/phpunit/tests/customize/setting.php

@@ -397 +397 @@
 
                 // Custom type that does not handle supplying the post value from the customize_value_{$id_base} filter.
                 $setting_id = 'custom_without_previewing_value_filter';
+
                 $setting = $this->manager->add_setting( $setting_id, array(
                         'type' => 'custom_preview_test',
                         'default' => 123,
                         'sanitize_callback' => array( $this->manager->nav_menus, 'intval_base10' ),
                 ) );
+
+                // When #36952 occurs, get_theme_mod() will still return the default
+                // value if no theme mod exists. Add one to test that it isn't returned.
+                set_theme_mod( $setting_id, 999 );
                 $this->assertSame( 123, $setting->value() );
+
                 $this->manager->set_post_value( $setting_id, '456' );
                 $setting->preview();
                 $this->assertSame( 456, $setting->value() );
 
                 unset( $this->custom_type_data_previewed, $this->custom_type_data_saved );
+                remove_theme_mod( $setting_id );
         }
 
         /**