Added regression test

Author: staabm

tests/end-to-end/regression/6382.phpt

@@ -0,0 +1,19 @@
+--TEST--
+https://github.com/sebastianbergmann/phpunit/issues/6382
+--FILE--
+<?php declare(strict_types=1);
+$_SERVER['argv'][] = '--do-not-cache-result';
+$_SERVER['argv'][] = '--no-configuration';
+$_SERVER['argv'][] = __DIR__ . '/6382/Issue6382Test.php';
+
+require_once __DIR__ . '/../../bootstrap.php';
+
+(new PHPUnit\TextUI\Application)->run($_SERVER['argv']);
+--EXPECTF--
+PHPUnit %s by Sebastian Bergmann and contributors.
+
+Runtime: %s
+
+
+Fatal error: Declaration of Greg0ire\PhpunitReproducer\Child6382::__invoke() must be compatible with Greg0ire\PhpunitReproducer\Ancestor6382::__invoke(): void in %sChild.php on line %d
+Fatal error: Premature end of PHP process when running Issue6382Test::testExample.

tests/end-to-end/regression/6382/Ancestor.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Greg0ire\PhpunitReproducer;
+
+interface Ancestor6382
+{
+    public function __invoke(): void;
+}

tests/end-to-end/regression/6382/Child.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Greg0ire\PhpunitReproducer;
+
+interface Child6382 extends Ancestor6382
+{
+    public function __invoke();
+}

tests/end-to-end/regression/6382/Issue6382Test.php

@@ -0,0 +1,15 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use Greg0ire\PhpunitReproducer\Child6382;
+
+class Issue6382Test extends TestCase
+{
+    public function testExample(): void
+    {
+        require_once __DIR__.'/Ancestor.php';
+        require_once __DIR__.'/Child.php';
+
+        new Child6382();
+    }
+}