Fix type of clone expression

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -126,6 +126,7 @@
 use PHPStan\Type\NullType;
 use PHPStan\Type\ObjectShapeType;
 use PHPStan\Type\ObjectType;
+use PHPStan\Type\ObjectWithoutClassType;
 use PHPStan\Type\ParserNodeTypeToPHPStanType;
 use PHPStan\Type\StaticType;
 use PHPStan\Type\StringType;
@@ -1243,7 +1244,18 @@ private function resolveType(string $exprString, Expr $node): Type
 		}
 
 		if ($node instanceof Expr\Clone_) {
-			return $this->getType($node->expr);
+			$cloneType = TypeCombinator::intersect($this->getType($node->expr), new ObjectWithoutClassType());
+
+			return TypeTraverser::map($cloneType, static function (Type $type, callable $traverse): Type {
+				if ($type instanceof UnionType || $type instanceof IntersectionType) {
+					return $traverse($type);
+				}
+				if ($type instanceof ThisType) {
+					return new StaticType($type->getClassReflection(), $type->getSubtractedType());
+				}
+
+				return $type;
+			});
 		}
 
 		if ($node instanceof Node\Scalar\Int_) {

tests/PHPStan/Analyser/nsrt/clone.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace CloneType;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	public function doFoo(?object $object, $mixed): void
+	{
+		assertType('object', clone $object);
+		assertType('object', clone $mixed);
+		assertType('static(CloneType\\Foo)', clone new $this);
+		assertType('static(CloneType\\Foo)', clone new static);
+		assertType(self::class, clone new self);
+	}
+
+}