Add non-regression test for dynamic static call with by-reference parameter

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

tests/PHPStan/Rules/Comparison/IfConstantConditionRuleTest.php

@@ -237,4 +237,10 @@ public function testBug6822(): void
 		$this->analyse([__DIR__ . '/../../Analyser/nsrt/bug-6822.php'], []);
 	}
 
+	public function testBug5020(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-5020.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Comparison/data/bug-5020.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Bug5020;
+
+interface ITransformer
+{
+	public static function Transform(string $theInput, bool &$theErrorEncountered): string;
+}
+
+class Transformer implements ITransformer
+{
+	public static function Transform(string $theInput, bool &$theErrorEncountered): string
+	{
+		if ($theInput === 'invalid') {
+			$theErrorEncountered = true;
+			return '';
+		}
+		return strtoupper(trim($theInput));
+	}
+}
+
+/**
+ * @param class-string<Transformer> $transformer
+ */
+function foo(string $transformer): void
+{
+	$input = ' asdasda asdasd ';
+	$error = false;
+	$output = $transformer::Transform($input, $error);
+	if ($error) {
+
+	}
+}