Fix DatePeriodConstructorReturnTypeExtension

src/Type/Php/DatePeriodConstructorReturnTypeExtension.php

@@ -32,19 +32,19 @@ public function isStaticMethodSupported(MethodReflection $methodReflection): boo
 		return $methodReflection->getName() === '__construct';
 	}
 
-	public function getTypeFromStaticMethodCall(MethodReflection $methodReflection, StaticCall $methodCall, Scope $scope): Type
+	public function getTypeFromStaticMethodCall(MethodReflection $methodReflection, StaticCall $methodCall, Scope $scope): ?Type
 	{
-		if (!isset($methodCall->getArgs()[0])) {
-			return new ObjectType(DatePeriod::class);
-		}
-
 		if (!$methodCall->class instanceof Name) {
-			return new ObjectType(DatePeriod::class);
+			return null;
 		}
 
 		$className = $scope->resolveName($methodCall->class);
 		if (strtolower($className) !== 'dateperiod') {
-			return new ObjectType($className);
+			return null;
+		}
+
+		if (!isset($methodCall->getArgs()[0])) {
+			return null;
 		}
 
 		$firstArgType = $scope->getType($methodCall->getArgs()[0]->value);
@@ -80,7 +80,7 @@ public function getTypeFromStaticMethodCall(MethodReflection $methodReflection,
 			]);
 		}
 
-		return new ObjectType(DatePeriod::class);
+		return null;
 	}
 
 }

tests/PHPStan/Rules/Functions/ReturnTypeRuleTest.php

@@ -357,6 +357,14 @@ public function testBug12274(): void
 		]);
 	}
 
+	public function testBug13484(): void
+	{
+		$this->checkExplicitMixed = true;
+		$this->checkNullables = true;
+
+		$this->analyse([__DIR__ . '/data/bug-13484.php'], []);
+	}
+
 	public function testBug9401(): void
 	{
 		$this->checkExplicitMixed = true;

tests/PHPStan/Rules/Functions/data/bug-13484.php

@@ -0,0 +1,15 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13484;
+
+class MyPeriod extends \DatePeriod {
+	protected array $arguments;
+	public function __construct(...$arguments) {
+		$this->arguments = $arguments;
+	}
+}
+
+function test(): MyPeriod
+{
+	return new MyPeriod();
+}