Ticket #55429: json.patch

.editorconfig

@@ -17 +17 @@
 indent_style = space
 indent_size = 2
 
+[*.json]
+indent_style = space
+indent_size = 4
+
 [*.md]
 trim_trailing_whitespace = false
 

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

@@ -338 +338 @@
 
                 if ( ! $this->template ) {
                         $this->template = $this->stylesheet;
-                        if ( ! file_exists( $this->theme_root . '/' . $this->stylesheet . '/index.php' ) ) {
+
+                        $index_php_path = $this->theme_root . '/' . $this->stylesheet . '/index.php';
+                        $index_html_path = $this->theme_root . '/' . $this->stylesheet . '/templates/index.html';
+
+                        if ( ! file_exists( $index_php_path ) &&  ! file_exists( $index_html_path ) ) {
                                 $error_message = sprintf(
                                         /* translators: 1: index.php, 2: Documentation URL, 3: style.css */
                                         __( 'Template is missing. Standalone themes need to have a %1$s template file. <a href="%2$s">Child themes</a> need to have a Template header in the %3$s stylesheet.' ),
-                                        '<code>index.php</code>',
+                                        '<code>index.php</code> or <code>templates/index.html</code>',
                                         __( 'https://developer.wordpress.org/themes/advanced-topics/child-themes/' ),
                                         '<code>style.css</code>'
                                 );

src/wp-includes/theme.php

@@ -857 +857 @@
                 return true;
         }
 
-        if ( ! file_exists( get_template_directory() . '/index.php' ) ) {
+        if ( ! file_exists( get_template_directory() . '/index.php' ) && ! file_exists( get_template_directory() . '/templates/index.html' ) ) {
                 // Invalid.
         } elseif ( ! file_exists( get_template_directory() . '/style.css' ) ) {
                 // Invalid.