From 6159843e047b571c709951e52ce11fb8f349a646 Mon Sep 17 00:00:00 2001
From: Nicolai Ehrhardt <245527909+predictor2718@users.noreply.github.com>
Date: Tue, 28 Apr 2026 21:39:02 +0200
Subject: [PATCH 1/3] Fix phpstan/phpstan#13539: property.notFound in chained
 isset() with checkDynamicProperties

---
 .../Properties/AccessPropertiesCheck.php      |  4 +++
 .../Properties/AccessPropertiesRuleTest.php   | 14 ++++++++++
 .../Rules/Properties/data/bug-13539.php       | 28 +++++++++++++++++++
 3 files changed, 46 insertions(+)
 create mode 100644 tests/PHPStan/Rules/Properties/data/bug-13539.php

diff --git a/src/Rules/Properties/AccessPropertiesCheck.php b/src/Rules/Properties/AccessPropertiesCheck.php
index b1e0514e8e3..05402130386 100644
--- a/src/Rules/Properties/AccessPropertiesCheck.php
+++ b/src/Rules/Properties/AccessPropertiesCheck.php
@@ -144,6 +144,10 @@ private function processSingleProperty(Scope $scope, PropertyFetch $node, string
 				if ($maybePropertyReflection !== null && $maybePropertyReflection->isDummy()->no()) {
 					return [];
 				}
+
+				if ($type->getObjectClassNames() === []) {
+					return [];
+				}
 			}
 		}
 
diff --git a/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php b/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php
index eeda2fb9222..266cd5450a5 100644
--- a/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php
+++ b/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php
@@ -1272,4 +1272,18 @@ public function testBug13537(): void
 		$this->analyse([__DIR__ . '/data/bug-13537.php'], $errors);
 	}
 
+	public function testBug13539(): void
+	{
+		$this->checkThisOnly = false;
+		$this->checkUnionTypes = true;
+		$this->checkDynamicProperties = true;
+		$this->analyse([__DIR__ . '/data/bug-13539.php'], [
+			[
+				'Access to an undefined property object::$baz.',
+				26,
+				'Learn more: <fg=cyan>https://phpstan.org/blog/solving-phpstan-access-to-undefined-property</>',
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Properties/data/bug-13539.php b/tests/PHPStan/Rules/Properties/data/bug-13539.php
new file mode 100644
index 00000000000..f55319aa343
--- /dev/null
+++ b/tests/PHPStan/Rules/Properties/data/bug-13539.php
@@ -0,0 +1,28 @@
+<?php
+
+function broken(string $x): void {
+	$tmp = json_decode($x, false);
+	if (!isset($tmp->foo) || !isset($tmp->bar)) {
+	}
+}
+
+function works(string $x): void {
+	$tmp = json_decode($x, false);
+	if (!isset($tmp->foo, $tmp->bar)) {
+	}
+}
+
+function works_too(string $x): void {
+	/** @var stdClass $tmp */
+	$tmp = json_decode($x, false);
+	if (!isset($tmp->foo) || !isset($tmp->bar)) {
+	}
+}
+
+function also_ok(mixed $tmp): void {
+	if (isset($tmp->foo) && isset($tmp->bar)) {
+		echo $tmp->foo;
+		echo $tmp->bar;
+		echo $tmp->baz; // intentional: baz not checked by isset
+	}
+}

From 034a1a36cc47bdff38b64aceec6ab5d6b8024d71 Mon Sep 17 00:00:00 2001
From: Nicolai Ehrhardt <245527909+predictor2718@users.noreply.github.com>
Date: Tue, 28 Apr 2026 21:58:15 +0200
Subject: [PATCH 2/3] Update testBug13529 to expect no errors after fix for
 #13539

---
 .../Analyser/AnalyserWithCheckDynamicPropertiesTest.php       | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tests/PHPStan/Analyser/AnalyserWithCheckDynamicPropertiesTest.php b/tests/PHPStan/Analyser/AnalyserWithCheckDynamicPropertiesTest.php
index b6a160de932..5538225e419 100644
--- a/tests/PHPStan/Analyser/AnalyserWithCheckDynamicPropertiesTest.php
+++ b/tests/PHPStan/Analyser/AnalyserWithCheckDynamicPropertiesTest.php
@@ -12,9 +12,7 @@ class AnalyserWithCheckDynamicPropertiesTest extends PHPStanTestCase
 	public function testBug13529(): void
 	{
 		$errors = $this->runAnalyse(__DIR__ . '/data/bug-13529.php');
-		$this->assertCount(1, $errors);
-		$this->assertSame('Access to an undefined property object::$bar.', $errors[0]->getMessage());
-		$this->assertSame(8, $errors[0]->getLine());
+		$this->assertCount(0, $errors);
 	}
 
 	/**

From 4f11c353eca710d8021b9c0647d4333086601d8e Mon Sep 17 00:00:00 2001
From: Nicolai Ehrhardt <245527909+predictor2718@users.noreply.github.com>
Date: Tue, 28 Apr 2026 22:02:52 +0200
Subject: [PATCH 3/3] Fix bug-13539 test for PHP 7.4 compatibility (use PHPDoc
 instead of native mixed)

---
 tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php | 2 +-
 tests/PHPStan/Rules/Properties/data/bug-13539.php           | 5 ++++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php b/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php
index 266cd5450a5..674dd0beb77 100644
--- a/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php
+++ b/tests/PHPStan/Rules/Properties/AccessPropertiesRuleTest.php
@@ -1280,7 +1280,7 @@ public function testBug13539(): void
 		$this->analyse([__DIR__ . '/data/bug-13539.php'], [
 			[
 				'Access to an undefined property object::$baz.',
-				26,
+				29,
 				'Learn more: <fg=cyan>https://phpstan.org/blog/solving-phpstan-access-to-undefined-property</>',
 			],
 		]);
diff --git a/tests/PHPStan/Rules/Properties/data/bug-13539.php b/tests/PHPStan/Rules/Properties/data/bug-13539.php
index f55319aa343..845c927a48c 100644
--- a/tests/PHPStan/Rules/Properties/data/bug-13539.php
+++ b/tests/PHPStan/Rules/Properties/data/bug-13539.php
@@ -19,7 +19,10 @@ function works_too(string $x): void {
 	}
 }
 
-function also_ok(mixed $tmp): void {
+/**
+ * @param mixed $tmp
+ */
+function also_ok($tmp): void {
 	if (isset($tmp->foo) && isset($tmp->bar)) {
 		echo $tmp->foo;
 		echo $tmp->bar;