ext/standard: Validate scandir() sorting_order parameter

Author: arshidkv12

ext/standard/tests/dir/scandir_invalid_flag.phpt

@@ -0,0 +1,42 @@
+--TEST--
+scandir() flag validation and behavior
+--FILE--
+<?php
+
+echo "== Valid flags ==\n";
+
+$valid_flags = [
+    SCANDIR_SORT_ASCENDING,
+    SCANDIR_SORT_DESCENDING,
+    SCANDIR_SORT_NONE,
+];
+
+foreach ($valid_flags as $flag) {
+    $result = scandir(__DIR__, $flag);
+    echo is_array($result) ? "OK\n" : "FAIL\n";
+}
+
+echo "== Invalid flags ==\n";
+
+$invalid_flags = [-1, 3, 999, PHP_INT_MAX];
+
+foreach ($invalid_flags as $flag) {
+    try {
+        scandir(__DIR__, $flag);
+        echo "FAIL\n";
+    } catch (ValueError $e) {
+        echo "OK\n";
+    }
+}
+
+?>
+--EXPECT--
+== Valid flags ==
+OK
+OK
+OK
+== Invalid flags ==
+OK
+OK
+OK
+OK