Index: wp-includes/post-template.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- wp-includes/post-template.php	(revision )
+++ wp-includes/post-template.php	(revision )
@@ -536,6 +536,14 @@
 			$classes[] = 'post-type-paged-' . $page;
 	}
 
+    /** Add child-theme-<Name> to default body classes */
+    if ( is_child_theme() ) {
+        $classes[] = 'child-theme-' . sanitize_html_class( get_option( 'stylesheet' ) );
+    }
+
+    /** Add theme-<Name> to default body classes */
+    $classes[] = 'theme-' . sanitize_html_class( get_option( 'template' ) );
+
 	if ( ! empty( $class ) ) {
 		if ( !is_array( $class ) )
 			$class = preg_split( '#\s+#', $class );