Recurse into parent expression in IssetCheck and MutatingScope::issetCheck when property has propagated error

src/Analyser/MutatingScope.php

@@ -1087,6 +1087,14 @@ public function issetCheck(Expr $expr, callable $typeCallback, ?bool $result = n
 			}
 
 			if ($result !== null) {
+				if ($expr instanceof Node\Expr\PropertyFetch) {
+					return $this->issetCheck($expr->var, $typeCallback, $result);
+				}
+
+				if ($expr->class instanceof Expr) {
+					return $this->issetCheck($expr->class, $typeCallback, $result);
+				}
+
 				return $result;
 			}
 

src/Rules/IssetCheck.php

@@ -196,6 +196,14 @@ static function (Type $type) use ($typeMessageCallback): ?string {
 			$propertyDescription = $this->propertyDescriptor->describeProperty($propertyReflection, $scope, $expr);
 			$propertyType = $propertyReflection->getWritableType();
 			if ($error !== null) {
+				if ($expr instanceof Node\Expr\PropertyFetch) {
+					return $this->check($expr->var, $scope, $operatorDescription, $identifier, $typeMessageCallback, $error);
+				}
+
+				if ($expr->class instanceof Expr) {
+					return $this->check($expr->class, $scope, $operatorDescription, $identifier, $typeMessageCallback, $error);
+				}
+
 				return $error;
 			}
 			if (!$this->checkAdvancedIsset) {

tests/PHPStan/Analyser/nsrt/bug-14555.php

@@ -0,0 +1,26 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug14555Nsrt;
+
+use function PHPStan\Testing\assertType;
+
+class ValueObject {
+	function __construct(
+		public readonly string $value,
+	) {}
+}
+
+class SomeDTO {
+	function __construct(
+		public readonly ValueObject $value,
+	) {}
+}
+
+/** @param array<string, list<SomeDTO>> $array */
+function testCoalesceType(array $array): void
+{
+	$someValue = $array['someKey'][0]->value->value ?? null;
+	assertType('string|null', $someValue);
+}

tests/PHPStan/Rules/Variables/IssetRuleTest.php

@@ -531,6 +531,13 @@ public function testBug9503(): void
 		$this->analyse([__DIR__ . '/data/bug-9503.php'], []);
 	}
 
+	public function testBug14555(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14555.php'], []);
+	}
+
 	public function testBug14393(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;

tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php

@@ -397,6 +397,12 @@ public function testBug14458(): void
 		$this->analyse([__DIR__ . '/data/bug-14458.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.1.0')]
+	public function testBug14555(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14555.php'], []);
+	}
+
 	#[RequiresPhp('>= 8.1.0')]
 	public function testBug14459(): void
 	{

tests/PHPStan/Rules/Variables/data/bug-14555.php

@@ -0,0 +1,50 @@
+<?php // lint >= 8.1
+
+declare(strict_types = 1);
+
+namespace Bug14555;
+
+class ValueObject {
+	function __construct(
+		public readonly string $value,
+	) {}
+}
+
+class SomeDTO {
+	function __construct(
+        public readonly ValueObject $value,
+    ) {}
+}
+
+class StaticHolder {
+	public static ValueObject $value;
+}
+
+/** @param array<string, list<SomeDTO>> $array */
+function exampleNullCoalesce(array $array): void
+{
+	$someValue = $array['someKey'][0]->value->value ?? null;
+
+	$dto = $array['someKey'][0] ?? null;
+	$someValue2 = $dto->value->value ?? null;
+}
+
+/** @param array<string, list<SomeDTO>> $array */
+function exampleIsset(array $array): void
+{
+	if (isset($array['someKey'][0]->value->value)) {
+		echo 'yes';
+	}
+}
+
+/** @param array<string, list<SomeDTO>> $array */
+function exampleNullCoalesceAssign(array $array): void
+{
+	$someValue = $array['someKey'][0]->value->value ??= 'default';
+}
+
+/** @param array<string, list<StaticHolder>> $array */
+function exampleStaticProperty(array $array): void
+{
+	$someValue = $array['someKey'][0]::$value->value ?? null;
+}