Add reproducing test case for #3739

tests/end-to-end/regression/GitHub/3739.phpt

@@ -0,0 +1,19 @@
+--TEST--
+https://github.com/sebastianbergmann/phpunit/issues/3739
+--FILE--
+<?php declare(strict_types=1);
+$_SERVER['argv'][1] = '--no-configuration';
+$_SERVER['argv'][2] = 'Issue3739Test';
+$_SERVER['argv'][3] = __DIR__ . '/3739/Issue3739Test.php';
+
+require __DIR__ . '/../../../bootstrap.php';
+
+PHPUnit\TextUI\Command::main();
+--EXPECTF--
+PHPUnit %s by Sebastian Bergmann and contributors.
+
+.                                                                   1 / 1 (100%)
+
+Time: %s, Memory: %s
+
+OK (1 test, 1 assertion)

tests/end-to-end/regression/GitHub/3739/Issue3739Test.php

@@ -0,0 +1,20 @@
+<?php declare(strict_types=1);
+namespace Issue3739;
+
+use PHPUnit\Framework\TestCase;
+
+class Issue3739
+{
+    public function unlinkFileThatDoesNotExist(): bool
+    {
+        return @unlink(__DIR__ . '/DOES_NOT_EXIST');
+    }
+}
+
+final class Issue3739Test extends TestCase
+{
+    public function testOne(): void
+    {
+        $this->assertFalse((new Issue3739())->unlinkFileThatDoesNotExist());
+    }
+}