From ee7187c8d652c3c40ff4319a5a42f0aaa27c2a54 Mon Sep 17 00:00:00 2001
From: kkmuffme <11071985+kkmuffme@users.noreply.github.com>
Date: Sun, 4 Feb 2024 11:51:57 +0100
Subject: [PATCH] directory_separator optional wrong

---
 src/Psalm/Config.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index bebf47159..3e440e380 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -1817,7 +1817,13 @@ class Config
     public function shortenFileName(string $to): string
     {
         if (!is_file($to)) {
-            return preg_replace('/^' . preg_quote($this->base_dir . DIRECTORY_SEPARATOR, '/') . '?/', '', $to, 1);
+            // if cwd is the root directory it will be just the directory separator - trim it off first
+            return preg_replace(
+                '/^' . preg_quote(rtrim($this->base_dir, DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR, '/') . '/',
+                '',
+                $to,
+                1,
+            );
         }
 
         $from = $this->base_dir;