Index: wp-includes/functions.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
--- a/wp-includes/functions.php	(revision 50070)
+++ b/wp-includes/functions.php	(date 1611931996233)
@@ -7734,7 +7734,7 @@
 	$path = untrailingslashit( $path );
 	unset( $directory_cache[ $path ] );
 
-	while ( DIRECTORY_SEPARATOR !== $path && '.' !== $path && '..' !== $path ) {
+	while ( DIRECTORY_SEPARATOR !== $path && $path[ 0 ] . ':' . DIRECTORY_SEPARATOR !== $path && '.' !== $path && '..' !== $path ) {
 		$path = dirname( $path );
 		unset( $directory_cache[ $path ] );
 	}