Fix param-type specification interfering with root-expression types

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -1099,7 +1099,9 @@ private function specifyTypesForConstantStringBinaryExpression(
 			}
 
 			if ($type !== null) {
-				return $this->create($exprNode->getArgs()[0]->value, $type, $context, false, $scope, $rootExpr);
+				$callType = $this->create($exprNode, $constantType, $context, false, $scope, $rootExpr);
+				$argType = $this->create($exprNode->getArgs()[0]->value, $type, $context, false, $scope, $rootExpr);
+				return $callType->unionWith($argType);
 			}
 		}
 

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -1256,6 +1256,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/extract.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/image-size.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/base64_decode.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-9404.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-9404.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Bug9404;
+
+use function PHPStan\Testing\assertType;
+
+function foo(int|string $x): void
+{
+	if (gettype($x) === 'integer') {
+		assertType("'integer'", gettype($x));
+	}
+}