From c16d779bca1d998c5d7a27a9f94650a3aefd0907 Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Sun, 25 Oct 2020 22:16:43 -0400
Subject: [PATCH] Fix #4397 - allow offsetGet on inside isset

---
 .../Statements/Expression/Call/MethodCallAnalyzer.php      | 1 +
 tests/ArrayAccessTest.php                                  | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/MethodCallAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/MethodCallAnalyzer.php
index 80b8976d3..3c48a6368 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/Call/MethodCallAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/Call/MethodCallAnalyzer.php
@@ -138,6 +138,7 @@ class MethodCallAnalyzer extends \Psalm\Internal\Analyzer\Statements\Expression\
             && $stmt->name instanceof PhpParser\Node\Identifier
             && $class_type->isNullable()
             && !$class_type->ignore_nullable_issues
+            && !($stmt->name->name === 'offsetGet' && $context->inside_isset)
         ) {
             if (IssueBuffer::accepts(
                 new PossiblyNullReference(
diff --git a/tests/ArrayAccessTest.php b/tests/ArrayAccessTest.php
index 25d38015b..fec6d60de 100644
--- a/tests/ArrayAccessTest.php
+++ b/tests/ArrayAccessTest.php
@@ -976,6 +976,13 @@ class ArrayAccessTest extends TestCase
                     test(["a", "b"]);
                     test(new ArrayObject(["a", "b"]));'
             ],
+            'nullCoalesceArrayAccess' => [
+                '<?php
+                    /** @param ArrayAccess<int, string> $a */
+                    function foo(?ArrayAccess $a) : void {
+                        echo $a[0] ?? "default";
+                    }'
+            ],
         ];
     }