Fix RuleLevelHelper

Author: VincentLanglet

src/Rules/RuleLevelHelper.php

@@ -190,7 +190,11 @@ private function findTypeToCheckImplementation(
 		bool $isTopLevel = false,
 	): FoundTypeResult
 	{
-		if (!$this->checkNullables && !$type->isNull()->yes()) {
+		if (
+			!$this->checkNullables
+			&& !$type->isNull()->yes()
+			&& !$unionTypeCriteriaCallback(new NullType())
+		) {
 			$type = TypeCombinator::removeNull($type);
 		}
 

tests/PHPStan/Levels/data/arrayOffsetAccess-10-missing.json

@@ -9,4 +9,4 @@
         "line": 7,
         "ignorable": true
     }
-]
+]

tests/PHPStan/Levels/data/arrayOffsetAccess-6.json

@@ -5,7 +5,7 @@
         "ignorable": true
     },
     {
-        "message": "Invalid array key type object.",
+        "message": "Possibly invalid array key type object|null.",
         "line": 20,
         "ignorable": true
     }