Pass-by-ref argument type passed to callable should be mixed after calling the callable

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -1828,6 +1828,14 @@ function (MutatingScope $scope) use ($expr, $nodeCallback, $context): Expression
 			$functionReflection = null;
 			$throwPoints = [];
 			if ($expr->name instanceof Expr) {
+				$nameType = $scope->getType($expr->name);
+				if ($nameType->isCallable()->yes()) {
+					$parametersAcceptor = ParametersAcceptorSelector::selectFromArgs(
+						$scope,
+						$expr->args,
+						$nameType->getCallableParametersAcceptors($scope)
+					);
+				}
 				$nameResult = $this->processExprNode($expr->name, $scope, $nodeCallback, $context->enterDeep());
 				$throwPoints = $nameResult->getThrowPoints();
 				$scope = $nameResult->getScope();

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -501,6 +501,7 @@ public function dataFileAsserts(): iterable
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-1870.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Methods/data/bug-5562.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-5615.php');
 	}
 
 	/**

tests/PHPStan/Analyser/data/bug-5615.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace Bug5615;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	public function doFoo(): void
+	{
+		$cb = function (bool &$save): void {
+
+		};
+		$save = true;
+		$cb($save);
+		assertType('mixed', $save);
+	}
+
+	/**
+	 * @param callable(bool &$save): void $call
+	 */
+	function get(callable $call) {
+		$save = true;
+		$call($save);
+		assertType('mixed', $save);
+	}
+
+}