Fixed detecting method signature compatibility

src/Rules/Methods/MethodSignatureRule.php

@@ -13,6 +13,7 @@
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Generic\TemplateTypeHelper;
 use PHPStan\Type\MixedType;
+use PHPStan\Type\ObjectType;
 use PHPStan\Type\StaticType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypehintHelper;
@@ -223,9 +224,10 @@ private function transformStaticType(ClassReflection $declaringClass, Type $type
 	{
 		return TypeTraverser::map($type, static function (Type $type, callable $traverse) use ($declaringClass): Type {
 			if ($type instanceof StaticType) {
-				$changedType = $type->changeBaseClass($declaringClass);
 				if ($declaringClass->isFinal()) {
-					$changedType = $changedType->getStaticObjectType();
+					$changedType = new ObjectType($declaringClass->getName());
+				} else {
+					$changedType = $type->changeBaseClass($declaringClass);
 				}
 				return $traverse($changedType);
 			}

tests/PHPStan/Rules/Methods/MethodSignatureRuleTest.php

@@ -333,4 +333,11 @@ public function testBug4707Two(): void
 		$this->analyse([__DIR__ . '/data/bug-4707-two.php'], []);
 	}
 
+	public function testBug4729(): void
+	{
+		$this->reportMaybes = true;
+		$this->reportStatic = true;
+		$this->analyse([__DIR__ . '/data/bug-4729.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-4729.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Bug4729;
+
+/** @template T of int */
+interface I
+{
+	/**
+	 * @return static
+	 */
+	function get(): I;
+}
+
+/**
+ * @template T of int
+ * @implements I<T>
+ */
+final class B implements I
+{
+	function get(): I
+	{
+		return $this;
+	}
+}
+
+/**
+ * @template T of int
+ * @implements I<T>
+ */
+class C implements I
+{
+	function get(): I
+	{
+		return $this;
+	}
+}