Add non regression test

Author: VincentLanglet

tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php

@@ -1001,6 +1001,11 @@ public function testBug10884(): void
 		$this->analyse([__DIR__ . '/data/bug-10884.php'], []);
 	}
 
+	public function testBug3761(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-3761.php'], []);
+	}
+
 	public function testBug13208(): void
 	{
 		$this->analyse([__DIR__ . '/data/bug-13208.php'], []);

tests/PHPStan/Rules/Comparison/data/bug-3761.php

@@ -0,0 +1,34 @@
+<?php declare(strict_types = 1);
+
+namespace Bug3761;
+
+class NamedTag{
+	public function getValue() : int{
+		return 1;
+	}
+}
+
+class SubclassOfNamedTag extends NamedTag{}
+
+class OtherSubclassOfNamedTag extends NamedTag{}
+
+class HelloWorld
+{
+	public function getTag() : ?NamedTag{
+		return new SubclassOfNamedTag();
+	}
+
+	/**
+	 * @phpstan-param class-string<NamedTag> $class
+	 */
+	public function getTagValue(string $class = NamedTag::class) : int{
+		$tag = $this->getTag();
+		if($tag instanceof $class){
+			return $tag->getValue();
+		}
+
+		throw new \RuntimeException(($tag === null ? "Missing" : get_class($tag)));
+	}
+}
+
+(new HelloWorld())->getTagValue(OtherSubclassOfNamedTag::class); //runtime exception: SubclassOfNamedTag