Changeset 63507

Timestamp:

09/06/2026 05:16:12 AM (13 hours ago)

Author:

westonruter

Message:

Themes: Set the template property when a theme is its own parent.

When a theme's Template header names the theme's own directory, WP_Theme::__construct() recorded the theme_child_invalid error and returned before assigning $this->template, leaving the property unset. As a result WP_Theme::get_template() returned null despite being documented as returning a string. That error scenario now assigns the stylesheet to $this->template and stores it in the theme cache, matching how the theme_no_stylesheet and theme_no_parent errors are already handled. The invalid-theme error itself is unchanged, and tests cover both the fresh and the cached construction paths.

Developed in ​https://github.com/WordPress/wordpress-develop/pull/10837.
Follow-up to r41601.

Props marian1, westonruter.
See #40820.
Fixes #64582.

Location:

trunk

Files:

• src/wp-includes/class-wp-theme.php (modified) (3 diffs)
• tests/phpunit/tests/theme/wpTheme.php (modified) (1 diff)

trunk/src/wp-includes/class-wp-theme.php

@@ -362 +362 @@
 
                 if ( ! $this->template && $this->stylesheet === $this->headers['Template'] ) {
-                        $this->errors = new WP_Error(
+                        $this->errors   = new WP_Error(
                                 'theme_child_invalid',
                                 sprintf(
@@ -370 +370 @@
                                 )
                         );
+                        $this->template = $this->stylesheet;
                         $this->cache_add(
                                 'theme',
@@ -378 +379 @@
                                         'errors'                 => $this->errors,
                                         'stylesheet'             => $this->stylesheet,
+                                        'template'               => $this->template,
                                 )
                         );

trunk/tests/phpunit/tests/theme/wpTheme.php

@@ -184 +184 @@
         }
 
+        /**
+         * Tests that a theme declaring itself as its own parent still has a template.
+         *
+         * The `theme_child_invalid` error must not leave `WP_Theme::$template` unset, as
+         * that makes `get_template()` return `null` and makes the template directory and
+         * its URI resolve to the theme root instead of the theme's own directory.
+         *
+         * @ticket 64582
+         *
+         * @covers WP_Theme::get_template
+         * @covers WP_Theme::get_template_directory
+         * @covers WP_Theme::get_template_directory_uri
+         */
+        public function test_child_theme_with_itself_as_parent_should_have_template_set() {
+                $theme = new WP_Theme( 'child-parent-itself', $this->theme_root );
+
+                $this->assertSame( 'child-parent-itself', $theme->get_template(), 'The template was not set to the stylesheet.' );
+                $this->assertSame(
+                        $this->theme_root . '/child-parent-itself',
+                        $theme->get_template_directory(),
+                        'The template directory did not resolve to the theme directory.'
+                );
+                $this->assertSame(
+                        $theme->get_theme_root_uri() . '/child-parent-itself',
+                        $theme->get_template_directory_uri(),
+                        'The template directory URI did not resolve to the theme directory.'
+                );
+        }
+
+        /**
+         * Tests that the template of a theme declaring itself as its own parent is cached.
+         *
+         * @ticket 64582
+         *
+         * @covers WP_Theme::__construct
+         * @covers WP_Theme::get_template
+         */
+        public function test_child_theme_with_itself_as_parent_should_have_template_set_when_read_from_cache() {
+                // Prime the theme cache.
+                new WP_Theme( 'child-parent-itself', $this->theme_root );
+
+                $theme = new WP_Theme( 'child-parent-itself', $this->theme_root );
+
+                $errors = $theme->errors();
+                $this->assertInstanceOf( WP_Error::class, $errors, 'The theme was not read back from the cache in an error state.' );
+                $this->assertSame( 'theme_child_invalid', $errors->get_error_code(), 'The theme was not read back from the cache with the expected error.' );
+                $this->assertSame( 'child-parent-itself', $theme->get_template(), 'The template was not restored from the cache.' );
+        }
 
         /**