Fix false positive about assign to protected property from a subclass

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -5655,7 +5655,7 @@ public function canWriteProperty(ExtendedPropertyReflection $propertyReflection)
 
 			if (
 				$classReflection->getName() === $propertyDeclaringClass->getName()
-				|| $classReflection->isSubclassOfClass($propertyDeclaringClass)
+				|| $classReflection->isSubclassOfClass($propertyDeclaringClass->removeFinalKeywordOverride())
 			) {
 				return true;
 			}
@@ -5712,7 +5712,7 @@ private function canAccessClassMember(ClassMemberReflection $classMemberReflecti
 
 			if (
 				$classReflection->getName() === $classMemberDeclaringClass->getName()
-				|| $classReflection->isSubclassOfClass($classMemberDeclaringClass)
+				|| $classReflection->isSubclassOfClass($classMemberDeclaringClass->removeFinalKeywordOverride())
 			) {
 				return true;
 			}

src/Reflection/ClassReflection.php

@@ -1702,6 +1702,48 @@ public function asFinal(): self
 		);
 	}
 
+	public function removeFinalKeywordOverride(): self
+	{
+		if ($this->getNativeReflection()->isFinal()) {
+			return $this;
+		}
+		if ($this->finalByKeywordOverride === false) {
+			return $this;
+		}
+		if (!$this->isClass()) {
+			return $this;
+		}
+		if ($this->isAbstract()) {
+			return $this;
+		}
+
+		return new self(
+			$this->reflectionProvider,
+			$this->initializerExprTypeResolver,
+			$this->fileTypeMapper,
+			$this->stubPhpDocProvider,
+			$this->phpDocInheritanceResolver,
+			$this->phpVersion,
+			$this->signatureMapProvider,
+			$this->deprecationProvider,
+			$this->attributeReflectionFactory,
+			$this->propertiesClassReflectionExtensions,
+			$this->methodsClassReflectionExtensions,
+			$this->allowedSubTypesClassReflectionExtensions,
+			$this->requireExtendsPropertiesClassReflectionExtension,
+			$this->requireExtendsMethodsClassReflectionExtension,
+			$this->displayName,
+			$this->reflection,
+			$this->anonymousFilename,
+			$this->resolvedTemplateTypeMap,
+			$this->stubPhpDocBlock,
+			$this->universalObjectCratesClasses,
+			null,
+			$this->resolvedCallSiteVarianceMap,
+			false,
+		);
+	}
+
 	public function getResolvedPhpDoc(): ?ResolvedPhpDocBlock
 	{
 		if ($this->stubPhpDocBlock !== null) {

tests/PHPStan/Rules/Properties/AccessPropertiesInAssignRuleTest.php

@@ -177,4 +177,9 @@ public function testAsymmetricVisibility(): void
 		]);
 	}
 
+	public function testBug13123(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-13123.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Properties/data/bug-13123.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Bug13123;
+
+class ControlGroup {}
+
+class Container {
+	protected ?ControlGroup $currentGroup = null;
+}
+
+class Multiplier extends Container {
+	protected function createContainer(): Container
+	{
+		$control = new Container();
+		$control->currentGroup = $this->currentGroup;
+
+		return $control;
+	}
+
+	protected function createContainer2(Container $control): Container
+	{
+		$control->currentGroup = $this->currentGroup;
+
+		return $control;
+	}
+
+
+}