Look if userland prototype has ReturnTypeWillChange or not

src/Rules/Methods/OverridingMethodRule.php

@@ -156,8 +156,8 @@ public function processNode(Node $node, Scope $scope): array
 			&& $this->phpVersion->hasTentativeReturnTypes()
 			&& $realPrototype->getTentativeReturnType() !== null
 			&& !$this->hasReturnTypeWillChangeAttribute($node->getOriginalNode())
+			&& count($prototype->getDeclaringClass()->getNativeReflection()->getMethod($prototype->getName())->getAttributes('ReturnTypeWillChange')) === 0
 		) {
-
 			if (!$this->methodParameterComparisonHelper->isReturnTypeCompatible($realPrototype->getTentativeReturnType(), $methodVariant->getNativeReturnType(), true)) {
 				$messages[] = RuleErrorBuilder::message(sprintf(
 					'Return type %s of method %s::%s() is not covariant with tentative return type %s of method %s::%s().',

tests/PHPStan/Rules/Methods/OverridingMethodRuleTest.php

@@ -682,4 +682,27 @@ public function testBug10101(): void
 		]);
 	}
 
+	public function testBug9615(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('Test requires PHP 8.1.');
+		}
+
+		$tipText = 'Make it covariant, or use the #[\ReturnTypeWillChange] attribute to temporarily suppress the error.';
+
+		$this->phpVersionId = PHP_VERSION_ID;
+		$this->analyse([__DIR__ . '/data/bug-9615.php'], [
+			[
+				'Return type mixed of method Bug9615\ExpectComplaintsHere::accept() is not covariant with tentative return type bool of method FilterIterator<mixed,mixed,Traversable<mixed, mixed>>::accept().',
+				19,
+				$tipText,
+			],
+			[
+				'Return type mixed of method Bug9615\ExpectComplaintsHere::getChildren() is not covariant with tentative return type RecursiveIterator|null of method RecursiveIterator<mixed,mixed>::getChildren().',
+				20,
+				$tipText,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/bug-9615.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Bug9615;
+
+class Filter extends \RecursiveFilterIterator {
+	#[\ReturnTypeWillChange]
+	public function accept() { return true; }
+
+	#[\ReturnTypeWillChange]
+	public function getChildren() { return null; }
+}
+
+class ThisShouldBeFine extends Filter {
+	public function accept() { return true; }
+	public function getChildren() { return null; }
+}
+
+class ExpectComplaintsHere extends \RecursiveFilterIterator {
+	public function accept() { return true; }
+	public function getChildren() { return null; }
+}