Fix phpstan/phpstan#13920: Anonymous class causes "variable might not be defined" issue

src/Analyser/ExprHandler/NewHandler.php

@@ -190,7 +190,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 						$constructorResult = $node;
 					}, StatementContext::createTopLevel());
 					if ($constructorResult !== null) {
-						$throwPoints = array_map(static fn (ThrowPoint $point) => InternalThrowPoint::createFromPublic($point), $constructorResult->getStatementResult()->getThrowPoints());
+						$throwPoints = array_map(static fn (ThrowPoint $point): InternalThrowPoint => InternalThrowPoint::createFromPublic($point)->replaceScope($scope), $constructorResult->getStatementResult()->getThrowPoints());
 						$impurePoints = $constructorResult->getImpurePoints();
 					}
 				} else {

src/Analyser/InternalThrowPoint.php

@@ -88,6 +88,11 @@ public function canContainAnyThrowable(): bool
 		return $this->canContainAnyThrowable;
 	}
 
+	public function replaceScope(MutatingScope $scope): self
+	{
+		return new self($scope, $this->type, $this->node, $this->explicit, $this->canContainAnyThrowable);
+	}
+
 	public function subtractCatchType(Type $catchType): self
 	{
 		return new self($this->scope, TypeCombinator::remove($this->type, $catchType), $this->node, $this->explicit, $this->canContainAnyThrowable);

tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php

@@ -1425,6 +1425,16 @@ public function testBug12373(): void
 		$this->analyse([__DIR__ . '/data/bug-12373.php'], []);
 	}
 
+	public function testBug13920(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = true;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-13920.php'], []);
+	}
+
 	public function testBug14117(): void
 	{
 		$this->cliArgumentsVariablesRegistered = true;

tests/PHPStan/Rules/Variables/data/bug-13920.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace Bug13920;
+
+class TestOutput {
+	public function __construct() {}
+}
+
+final class MyTest
+{
+	public function testRun(): void
+	{
+		$savedArgv = $_SERVER['argv'];
+
+		try {
+			$output = new class() extends TestOutput {
+				public function __construct()
+				{
+					parent::__construct();
+				}
+			};
+		} finally {
+			$_SERVER['argv'] = $savedArgv;
+		}
+	}
+}