From 2ab0e22b28ee3c9bd2a918c32170db1b6f9c68a0 Mon Sep 17 00:00:00 2001
From: Markus Staab <markus.staab@redaxo.de>
Date: Wed, 10 Sep 2025 14:51:53 +0200
Subject: [PATCH 1/4] Extract MutatingScope->isReadonlyPropertyFetchOnThis()

---
 src/Analyser/MutatingScope.php | 41 +++++++++++++++++++++-------------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 8be043daf2..de769ab442 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -315,24 +315,9 @@ private function rememberConstructorExpressions(array $currentExpressionTypes):
 					continue;
 				}
 			} elseif ($expr instanceof PropertyFetch) {
-				if (
-					!$expr->name instanceof Node\Identifier
-					|| !$expr->var instanceof Variable
-					|| $expr->var->name !== 'this'
-					|| !$this->phpVersion->supportsReadOnlyProperties()
-				) {
+				if (!$this->isReadonlyPropertyFetchOnThis($expr)) {
 					continue;
 				}
-
-				$propertyReflection = $this->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
-				if ($propertyReflection === null) {
-					continue;
-				}
-
-				$nativePropertyReflection = $propertyReflection->getNativeReflection();
-				if ($nativePropertyReflection === null || !$nativePropertyReflection->isReadOnly()) {
-						continue;
-				}
 			} elseif (!$expr instanceof ConstFetch && !$expr instanceof PropertyInitializationExpr) {
 				continue;
 			}
@@ -369,6 +354,30 @@ public function rememberConstructorScope(): self
 		);
 	}
 
+	private function isReadonlyPropertyFetchOnThis(PropertyFetch $expr): bool
+	{
+		if (
+			!$expr->name instanceof Node\Identifier
+			|| !$expr->var instanceof Variable
+			|| $expr->var->name !== 'this'
+			|| !$this->phpVersion->supportsReadOnlyProperties()
+		) {
+			return false;
+		}
+
+		$propertyReflection = $this->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
+		if ($propertyReflection === null) {
+			return false;
+		}
+
+		$nativePropertyReflection = $propertyReflection->getNativeReflection();
+		if ($nativePropertyReflection === null || !$nativePropertyReflection->isReadOnly()) {
+			return false;
+		}
+
+		return true;
+	}
+
 	/** @api */
 	public function isInClass(): bool
 	{

From 2cc1d8fc0640c2ae4f3cc0f25a238df335702e2f Mon Sep 17 00:00:00 2001
From: Markus Staab <markus.staab@redaxo.de>
Date: Wed, 10 Sep 2025 14:53:59 +0200
Subject: [PATCH 2/4] Remember narrowed types from the constructor from deep
 PropertyFetches

---
 src/Analyser/MutatingScope.php                | 37 +++++++++++--------
 ...remember-readonly-constructor-narrowed.php | 36 ++++++++++++++++++
 2 files changed, 58 insertions(+), 15 deletions(-)

diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index de769ab442..36039672af 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -356,23 +356,30 @@ public function rememberConstructorScope(): self
 
 	private function isReadonlyPropertyFetchOnThis(PropertyFetch $expr): bool
 	{
-		if (
-			!$expr->name instanceof Node\Identifier
-			|| !$expr->var instanceof Variable
-			|| $expr->var->name !== 'this'
-			|| !$this->phpVersion->supportsReadOnlyProperties()
-		) {
-			return false;
-		}
+		while ($expr instanceof PropertyFetch) {
+			if ($expr->var instanceof Variable) {
+				if (
+					! $expr->name instanceof Node\Identifier
+					|| !is_string($expr->var->name)
+					|| $expr->var->name !== 'this'
+				) {
+					return false;
+				}
+			} elseif (!$expr->var instanceof PropertyFetch) {
+				return false;
+			}
 
-		$propertyReflection = $this->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
-		if ($propertyReflection === null) {
-			return false;
-		}
+			$propertyReflection = $this->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
+			if ($propertyReflection === null) {
+				return false;
+			}
 
-		$nativePropertyReflection = $propertyReflection->getNativeReflection();
-		if ($nativePropertyReflection === null || !$nativePropertyReflection->isReadOnly()) {
-			return false;
+			$nativePropertyReflection = $propertyReflection->getNativeReflection();
+			if ($nativePropertyReflection === null || !$nativePropertyReflection->isReadOnly()) {
+				return false;
+			}
+
+			$expr = $expr->var;
 		}
 
 		return true;
diff --git a/tests/PHPStan/Analyser/nsrt/remember-readonly-constructor-narrowed.php b/tests/PHPStan/Analyser/nsrt/remember-readonly-constructor-narrowed.php
index 7ab2ea364f..55f8351fad 100644
--- a/tests/PHPStan/Analyser/nsrt/remember-readonly-constructor-narrowed.php
+++ b/tests/PHPStan/Analyser/nsrt/remember-readonly-constructor-narrowed.php
@@ -2,6 +2,7 @@
 
 namespace RememberReadOnlyConstructor;
 
+use LogicException;
 use function PHPStan\Testing\assertType;
 
 class HelloWorldReadonlyProperty {
@@ -107,3 +108,38 @@ public function doFoo() {
 		assertType('4|10', $this->i);
 	}
 }
+
+class Foo {
+	public readonly int $readonly;
+	public int $writable;
+
+	public function __construct()
+	{
+		$this->readonly = 5;
+		$this->writable = rand(0,1) ? 5 : 10;
+	}
+}
+
+class DeepPropertyFetching {
+	public readonly ?Foo $prop;
+
+	public function __construct() {
+		$this->prop = new Foo();
+		if($this->prop->readonly != 5) {
+			throw new LogicException();
+		}
+		if ($this->prop->writable != 5) {
+			throw new LogicException();
+		}
+
+		assertType(Foo::class, $this->prop);
+		assertType('5', $this->prop->readonly);
+		assertType('5', $this->prop->writable);
+	}
+
+	public function doFoo() {
+		assertType(Foo::class, $this->prop);
+		assertType('5', $this->prop->readonly);
+		assertType('int', $this->prop->writable);
+	}
+}

From 4518c9f997ebc91721b21b015c33764936c53652 Mon Sep 17 00:00:00 2001
From: Markus Staab <markus.staab@redaxo.de>
Date: Wed, 10 Sep 2025 15:02:57 +0200
Subject: [PATCH 3/4] added back php version check

---
 src/Analyser/MutatingScope.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 36039672af..4381d8f076 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -356,6 +356,10 @@ public function rememberConstructorScope(): self
 
 	private function isReadonlyPropertyFetchOnThis(PropertyFetch $expr): bool
 	{
+		if (!$this->phpVersion->supportsReadOnlyProperties()) {
+			return false;
+		}
+
 		while ($expr instanceof PropertyFetch) {
 			if ($expr->var instanceof Variable) {
 				if (

From a9046f648aa0c2468be9e3bfada9bc5030b158f7 Mon Sep 17 00:00:00 2001
From: Markus Staab <markus.staab@redaxo.de>
Date: Wed, 10 Sep 2025 15:30:04 +0200
Subject: [PATCH 4/4] refactor shouldInvalidateExpression()

---
 src/Analyser/MutatingScope.php | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 4381d8f076..caa7da7e93 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -315,7 +315,7 @@ private function rememberConstructorExpressions(array $currentExpressionTypes):
 					continue;
 				}
 			} elseif ($expr instanceof PropertyFetch) {
-				if (!$this->isReadonlyPropertyFetchOnThis($expr)) {
+				if (!$this->isReadonlyPropertyFetch($expr, true)) {
 					continue;
 				}
 			} elseif (!$expr instanceof ConstFetch && !$expr instanceof PropertyInitializationExpr) {
@@ -354,7 +354,7 @@ public function rememberConstructorScope(): self
 		);
 	}
 
-	private function isReadonlyPropertyFetchOnThis(PropertyFetch $expr): bool
+	private function isReadonlyPropertyFetch(PropertyFetch $expr, bool $allowOnlyOnThis): bool
 	{
 		if (!$this->phpVersion->supportsReadOnlyProperties()) {
 			return false;
@@ -363,9 +363,12 @@ private function isReadonlyPropertyFetchOnThis(PropertyFetch $expr): bool
 		while ($expr instanceof PropertyFetch) {
 			if ($expr->var instanceof Variable) {
 				if (
-					! $expr->name instanceof Node\Identifier
-					|| !is_string($expr->var->name)
-					|| $expr->var->name !== 'this'
+					$allowOnlyOnThis
+					&& (
+						! $expr->name instanceof Node\Identifier
+						|| !is_string($expr->var->name)
+						|| $expr->var->name !== 'this'
+					)
 				) {
 					return false;
 				}
@@ -4460,14 +4463,12 @@ private function shouldInvalidateExpression(string $exprStringToInvalidate, Expr
 			return false;
 		}
 
-		if ($this->phpVersion->supportsReadOnlyProperties() && $expr instanceof PropertyFetch && $expr->name instanceof Node\Identifier && $requireMoreCharacters) {
-			$propertyReflection = $this->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
-			if ($propertyReflection !== null) {
-				$nativePropertyReflection = $propertyReflection->getNativeReflection();
-				if ($nativePropertyReflection !== null && $nativePropertyReflection->isReadOnly()) {
-					return false;
-				}
-			}
+		if (
+			$expr instanceof PropertyFetch
+			&& $requireMoreCharacters
+			&& $this->isReadonlyPropertyFetch($expr, false)
+		) {
+			return false;
 		}
 
 		return true;