Fix type-specifying of expression involved in nullsafe property fetch

Author: ondrejmirtes

src/Analyser/TypeSpecifier.php

@@ -861,6 +861,10 @@ private function specifyTypesForConstantBinaryExpression(
 	{
 		if (!$context->null() && $constantType->getValue() === false) {
 			$types = $this->create($exprNode, $constantType, $context, false, $scope, $rootExpr);
+			if ($exprNode instanceof Expr\NullsafeMethodCall || $exprNode instanceof Expr\NullsafePropertyFetch) {
+				return $types;
+			}
+
 			return $types->unionWith($this->specifyTypesInCondition(
 				$scope,
 				$exprNode,
@@ -871,6 +875,10 @@ private function specifyTypesForConstantBinaryExpression(
 
 		if (!$context->null() && $constantType->getValue() === true) {
 			$types = $this->create($exprNode, $constantType, $context, false, $scope, $rootExpr);
+			if ($exprNode instanceof Expr\NullsafeMethodCall || $exprNode instanceof Expr\NullsafePropertyFetch) {
+				return $types;
+			}
+
 			return $types->unionWith($this->specifyTypesInCondition(
 				$scope,
 				$exprNode,

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1184,6 +1184,10 @@ public function dataFileAsserts(): iterable
 			yield from $this->gatherAssertTypes(__DIR__ . '/data/allowed-subtypes-enum.php');
 		}
 
+		if (PHP_VERSION_ID >= 80000) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-10071.php');
+		}
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/allowed-subtypes-datetime.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/allowed-subtypes-throwable.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Methods/data/bug-8174.php');

tests/PHPStan/Analyser/data/bug-10071.php

@@ -0,0 +1,22 @@
+<?php declare(strict_types=1); // lint >= 8.0
+
+namespace Bug10071;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+	public ?bool $bar = null;
+}
+
+
+function okIfBar(?Foo $foo = null): void
+{
+	if ($foo?->bar !== false) {
+		assertType(Foo::class . '|null', $foo);
+	} else {
+		assertType(Foo::class, $foo);
+	}
+
+	assertType(Foo::class . '|null', $foo);
+}