From 42380dbe874a306a95268e12b7e03568f12e6f4e Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Mon, 28 Nov 2022 11:58:05 +0100
Subject: [PATCH] Cleanup

---
 .../Statements/Expression/Fetch/ArrayFetchAnalyzer.php     | 7 ++++++-
 .../Internal/Type/Comparator/AtomicTypeComparator.php      | 4 ++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
index 8085cd042..8e43ee0f3 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/ArrayFetchAnalyzer.php
@@ -15,6 +15,7 @@ use Psalm\Internal\Analyzer\TraitAnalyzer;
 use Psalm\Internal\Codebase\TaintFlowGraph;
 use Psalm\Internal\Codebase\VariableUseGraph;
 use Psalm\Internal\DataFlow\DataFlowNode;
+use Psalm\Internal\Type\Comparator\AtomicTypeComparator;
 use Psalm\Internal\Type\Comparator\TypeComparisonResult;
 use Psalm\Internal\Type\Comparator\UnionTypeComparator;
 use Psalm\Internal\Type\TemplateInferredTypeReplacer;
@@ -1514,7 +1515,11 @@ class ArrayFetchAnalyzer
                 if ($type->is_list && (!is_numeric($key_value->value) || $key_value->value < 0)) {
                     $expected_offset_types[] = $type->getGenericKeyType();
                     $has_valid_offset = false;
-                } elseif (isset($properties[$key_value->value]) || $replacement_type) {
+                } elseif ((isset($properties[$key_value->value]) && !(
+                    $key_value->value === 0 && AtomicTypeComparator::isLegacyTListLike($type)
+                ))
+                    || $replacement_type
+                ) {
                     $has_valid_offset = true;
 
                     if ($replacement_type) {
diff --git a/src/Psalm/Internal/Type/Comparator/AtomicTypeComparator.php b/src/Psalm/Internal/Type/Comparator/AtomicTypeComparator.php
index 9cb7702b2..62a28ec99 100644
--- a/src/Psalm/Internal/Type/Comparator/AtomicTypeComparator.php
+++ b/src/Psalm/Internal/Type/Comparator/AtomicTypeComparator.php
@@ -729,7 +729,7 @@ class AtomicTypeComparator
         return $input_type_part->getKey() === $container_type_part->getKey();
     }
 
-    private static function isLegacyTListLike(Atomic $array): bool
+    public static function isLegacyTListLike(Atomic $array): bool
     {
         return $array instanceof TKeyedArray
             && $array->is_list
@@ -739,7 +739,7 @@ class AtomicTypeComparator
             && $array->properties[0]->equals($array->fallback_params[1], true, true, false)
         ;
     }
-    private static function isLegacyTNonEmptyListLike(Atomic $array): bool
+    public static function isLegacyTNonEmptyListLike(Atomic $array): bool
     {
         return $array instanceof TKeyedArray
             && $array->is_list