Regression test

Closes phpstan/phpstan#8668

Author: ondrejmirtes

tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php

@@ -1165,4 +1165,29 @@ public function testBug12645(): void
 		]);
 	}
 
+	public function testBug8668(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkUnionTypes = true;
+		$this->checkDynamicProperties = false;
+		$this->analyse([__DIR__ . '/data/bug-8668.php'], [
+			[
+				'Non-static access to static property Bug8668\Sample::$sample.',
+				9,
+			],
+			[
+				'Non-static access to static property Bug8668\Sample::$sample.',
+				10,
+			],
+			[
+				'Non-static access to static property Bug8668\Sample2::$sample.',
+				20,
+			],
+			[
+				'Non-static access to static property Bug8668\Sample2::$sample.',
+				21,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Properties/data/bug-8668.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Bug8668;
+
+class Sample {
+	private static string $sample = 'abc';
+
+	public function test(): void {
+		echo $this->sample;
+		echo isset($this->sample);
+
+		echo self::$sample; // ok
+	}
+}
+
+class Sample2 {
+	private static $sample = 'abc';
+
+	public function test(): void {
+		echo $this->sample;
+		echo isset($this->sample);
+
+		echo self::$sample; // ok
+	}
+}