add failling test

Author: staabm

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -1326,6 +1326,12 @@ public function testBug10924(): void
 		$this->analyse([__DIR__ . '/data/bug-10924.php'], []);
 	}
 
+	public function testBug8985(): void
+	{
+		$this->checkExplicitMixed = true;
+		$this->analyse([__DIR__ . '/data/bug-8985.php'], []);
+	}
+
 	public function testBug11430(): void
 	{
 		$this->analyse([__DIR__ . '/../../Analyser/nsrt/bug-11430.php'], []);

tests/PHPStan/Rules/Methods/data/bug-8985.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Bug8985;
+
+class HelloWorld
+{
+	/**
+	 * @return array<string, callable>
+	 */
+	protected function getDefaultFunctions(): array
+	{
+		/** @var array<string, callable> $x */
+		$x = (new Defaults())->getFunctions();
+		return $x;
+	}
+}
+
+class HelloWorld2
+{
+	/**
+	 * @return array<string, callable>
+	 */
+	protected function getDefaultFunctions(): array
+	{
+		/** @var array<string, callable> */
+		return (new Defaults())->getFunctions();
+	}
+}
+
+class Defaults
+{
+	public function getFunctions(): mixed
+	{
+		return [];
+	}
+}