From 451d5fbc7b37650d5a14f92047d8ee9544da57ed Mon Sep 17 00:00:00 2001
From: Yohta Kimura <kitakita7617@gmail.com>
Date: Sun, 24 Apr 2022 17:25:24 +0900
Subject: [PATCH 1/2] add failing test case for multiple isset var undefined
 variable false positive

---
 .../Rules/Variables/DefinedVariableRuleTest.php   |  9 +++++++++
 tests/PHPStan/Rules/Variables/data/bug-3601.php   | 15 +++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 tests/PHPStan/Rules/Variables/data/bug-3601.php

diff --git a/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php b/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
index 6349d31808..eb266e470d 100644
--- a/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
@@ -862,4 +862,13 @@ public function testBug6112(): void
 		$this->analyse([__DIR__ . '/data/bug-6112.php'], []);
 	}
 
+	public function testBug3601(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = true;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+		$this->analyse([__DIR__ . '/data/bug-3601.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Variables/data/bug-3601.php b/tests/PHPStan/Rules/Variables/data/bug-3601.php
new file mode 100644
index 0000000000..4930ab2f49
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-3601.php
@@ -0,0 +1,15 @@
+<?php declare(strict_types = 1);
+
+namespace Bug3601;
+
+if (rand(0, 1)) {
+	$a = 'b';
+}
+
+if (rand(0, 1)) {
+	$c = ['b' => 'everything is fine'];
+}
+
+if (isset($a, $c, $c[$a])) {
+	echo $c[$a];
+}

From 214d4327464a37d926a417ace79c2067a24664fb Mon Sep 17 00:00:00 2001
From: Yohta Kimura <kitakita7617@gmail.com>
Date: Sun, 24 Apr 2022 17:29:42 +0900
Subject: [PATCH 2/2] unset currentlyAllowedUndefinedExpression after isset
 scope ends

---
 src/Analyser/NodeScopeResolver.php | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index 4a7a75af33..685b5edf6c 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -2383,6 +2383,8 @@ static function (?Type $offsetType, Type $valueType) use (&$arrayType): void {
 				$hasYield = $hasYield || $result->hasYield();
 				$throwPoints = array_merge($throwPoints, $result->getThrowPoints());
 				$nonNullabilityResults[] = $nonNullabilityResult;
+			}
+			foreach (array_reverse($expr->vars) as $var) {
 				$scope = $this->lookForUnsetAllowedUndefinedExpressions($scope, $var);
 			}
 			foreach (array_reverse($nonNullabilityResults) as $nonNullabilityResult) {