From 597bfd05bef2f23bf6ac2de50f983ad6849106a6 Mon Sep 17 00:00:00 2001
From: Sebastian Bergmann <sb@sebastian-bergmann.de>
Date: Sat, 13 Aug 2022 10:05:53 +0200
Subject: [PATCH] Closes #5022

---
 .psalm/baseline.xml      |  8 -----
 ChangeLog-9.5.md         |  1 +
 src/Util/ExcludeList.php | 69 ++++++++++++++++++++++------------------
 3 files changed, 39 insertions(+), 39 deletions(-)

diff --git a/.psalm/baseline.xml b/.psalm/baseline.xml
index b44554ba658..26a42470677 100644
--- a/.psalm/baseline.xml
+++ b/.psalm/baseline.xml
@@ -1294,9 +1294,6 @@
     </MissingReturnType>
   </file>
   <file src="src/Util/ExcludeList.php">
-    <DocblockTypeContradiction occurrences="1">
-      <code>self::$directories === null</code>
-    </DocblockTypeContradiction>
     <MissingThrowsDocblock occurrences="1"/>
   </file>
   <file src="src/Util/Filter.php">
@@ -1430,11 +1427,6 @@
       <code>$stream</code>
     </PropertyNotSetInConstructor>
   </file>
-  <file src="src/Util/Reflection.php">
-    <PossiblyNullArgument occurrences="1">
-      <code>$filter</code>
-    </PossiblyNullArgument>
-  </file>
   <file src="src/Util/Test.php">
     <MissingReturnType occurrences="1">
       <code>sanitizeVersionNumber</code>
diff --git a/ChangeLog-9.5.md b/ChangeLog-9.5.md
index 0b8a1287649..fb791cc26d6 100644
--- a/ChangeLog-9.5.md
+++ b/ChangeLog-9.5.md
@@ -8,6 +8,7 @@ All notable changes of the PHPUnit 9.5 release series are documented in this fil
 
 * [#5015](https://github.com/sebastianbergmann/phpunit/pull/5015): Ukraine banner unreadable on black background
 * [#5020](https://github.com/sebastianbergmann/phpunit/issues/5020): PHPUnit 9 breaks loading of PSR-0/PEAR style classes
+* [#5022](https://github.com/sebastianbergmann/phpunit/issues/5022): `ExcludeList::addDirectory()` does not work correctly
 
 ## [9.5.21] - 2022-06-19
 
diff --git a/src/Util/ExcludeList.php b/src/Util/ExcludeList.php
index 5c52fd54a92..7cfcf872a6d 100644
--- a/src/Util/ExcludeList.php
+++ b/src/Util/ExcludeList.php
@@ -166,7 +166,12 @@ final class ExcludeList
     /**
      * @var string[]
      */
-    private static $directories;
+    private static $directories = [];
+
+    /**
+     * @var bool
+     */
+    private static $initialized = false;
 
     public static function addDirectory(string $directory): void
     {
@@ -219,39 +224,41 @@ public function isExcluded(string $file): bool
      */
     private function initialize(): void
     {
-        if (self::$directories === null) {
-            self::$directories = [];
-
-            foreach (self::EXCLUDED_CLASS_NAMES as $className => $parent) {
-                if (!class_exists($className)) {
-                    continue;
-                }
-
-                try {
-                    $directory = (new ReflectionClass($className))->getFileName();
-                    // @codeCoverageIgnoreStart
-                } catch (ReflectionException $e) {
-                    throw new Exception(
-                        $e->getMessage(),
-                        (int) $e->getCode(),
-                        $e
-                    );
-                }
-                // @codeCoverageIgnoreEnd
-
-                for ($i = 0; $i < $parent; $i++) {
-                    $directory = dirname($directory);
-                }
-
-                self::$directories[] = $directory;
+        if (self::$initialized) {
+            return;
+        }
+
+        foreach (self::EXCLUDED_CLASS_NAMES as $className => $parent) {
+            if (!class_exists($className)) {
+                continue;
             }
 
-            // Hide process isolation workaround on Windows.
-            if (DIRECTORY_SEPARATOR === '\\') {
-                // tempnam() prefix is limited to first 3 chars.
-                // @see https://php.net/manual/en/function.tempnam.php
-                self::$directories[] = sys_get_temp_dir() . '\\PHP';
+            try {
+                $directory = (new ReflectionClass($className))->getFileName();
+                // @codeCoverageIgnoreStart
+            } catch (ReflectionException $e) {
+                throw new Exception(
+                    $e->getMessage(),
+                    (int) $e->getCode(),
+                    $e
+                );
             }
+            // @codeCoverageIgnoreEnd
+
+            for ($i = 0; $i < $parent; $i++) {
+                $directory = dirname($directory);
+            }
+
+            self::$directories[] = $directory;
         }
+
+        // Hide process isolation workaround on Windows.
+        if (DIRECTORY_SEPARATOR === '\\') {
+            // tempnam() prefix is limited to first 3 chars.
+            // @see https://php.net/manual/en/function.tempnam.php
+            self::$directories[] = sys_get_temp_dir() . '\\PHP';
+        }
+
+        self::$initialized = true;
     }
 }