From e45619809406ec7374a496ad8c205e1e2ec141aa Mon Sep 17 00:00:00 2001
From: Martin Herndl <martin@herndl.org>
Date: Fri, 18 Mar 2022 22:00:14 +0100
Subject: [PATCH] Fix array_filter narrowing with explicit null callback

---
 .../Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php  | 3 +--
 tests/PHPStan/Analyser/data/array-filter.php                  | 4 ++--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php b/src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php
index bf0eb42757..69fa0303cc 100644
--- a/src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php
+++ b/src/Type/Php/ArrayFilterFunctionReturnTypeReturnTypeExtension.php
@@ -32,7 +32,6 @@
 use function array_map;
 use function count;
 use function is_string;
-use function strtolower;
 
 class ArrayFilterFunctionReturnTypeReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
@@ -63,7 +62,7 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 			]);
 		}
 
-		if ($callbackArg === null || ($callbackArg instanceof ConstFetch && strtolower($callbackArg->name->parts[0]) === 'null')) {
+		if ($callbackArg === null) {
 			return TypeCombinator::union(
 				...array_map([$this, 'removeFalsey'], TypeUtils::getArrays($arrayArgType)),
 			);
diff --git a/tests/PHPStan/Analyser/data/array-filter.php b/tests/PHPStan/Analyser/data/array-filter.php
index f5d1e181fe..3d9b48ec08 100644
--- a/tests/PHPStan/Analyser/data/array-filter.php
+++ b/tests/PHPStan/Analyser/data/array-filter.php
@@ -30,8 +30,8 @@ function withoutCallback(array $map1, array $map2, array $map3): void
 	assertType('array<string, float|int<min, -1>|int<1, max>|non-empty-string|true>', $filtered1);
 
 	$filtered2 = array_filter($map2, null, ARRAY_FILTER_USE_KEY);
-	assertType('array<string, float|int<min, -1>|int<1, max>|non-empty-string|true>', $filtered2);
+	assertType('array<string, bool|float|int|string>', $filtered2);
 
 	$filtered3 = array_filter($map3, null, ARRAY_FILTER_USE_BOTH);
-	assertType('array<string, float|int<min, -1>|int<1, max>|non-empty-string|true>', $filtered3);
+	assertType('array<string, bool|float|int|string>', $filtered3);
 }