From 6ad5e1c013a0d56d440e4c0722af56a3a6859dfc Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Thu, 1 Oct 2020 15:07:25 -0400
Subject: [PATCH] Fix #4264 - prevent crash when analysing file with duplicate
 classes

---
 .../Internal/PhpVisitor/ReflectorVisitor.php  | 12 +++++++++-
 tests/IncludeTest.php                         | 22 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php b/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php
index 22ac8dae5..22c3f5f60 100644
--- a/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php
+++ b/src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php
@@ -146,6 +146,11 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements PhpParse
      */
     private $classlike_type_aliases = [];
 
+    /**
+     * @var array<int, bool>
+     */
+    private $bad_classes = [];
+
     public function __construct(
         Codebase $codebase,
         FileStorage $file_storage,
@@ -285,7 +290,8 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements PhpParse
             }
 
             if ($this->registerClassLike($node) === false) {
-                return PhpParser\NodeTraverser::STOP_TRAVERSAL;
+                $this->bad_classes[\spl_object_id($node)] = true;
+                return PhpParser\NodeTraverser::DONT_TRAVERSE_CHILDREN;
             }
         } elseif (($node instanceof PhpParser\Node\Expr\New_
                 || $node instanceof PhpParser\Node\Expr\Instanceof_
@@ -575,6 +581,10 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements PhpParse
                 return null;
             }
 
+            if (isset($this->bad_classes[\spl_object_id($node)])) {
+                return null;
+            }
+
             if (!$this->fq_classlike_names) {
                 throw new \LogicException('$this->fq_classlike_names should not be empty');
             }
diff --git a/tests/IncludeTest.php b/tests/IncludeTest.php
index 63c2ca022..16ab53323 100644
--- a/tests/IncludeTest.php
+++ b/tests/IncludeTest.php
@@ -599,6 +599,28 @@ class IncludeTest extends TestCase
                     getcwd() . DIRECTORY_SEPARATOR . 'file2.php',
                 ],
             ],
+            'noCrash' => [
+                'files' => [
+                    getcwd() . DIRECTORY_SEPARATOR . 'classes.php' => '<?php
+                        // one.php
+
+                        if (true) {
+                            class One {}
+                        }
+                        else {
+                            class One {}
+                        }
+
+                        class Two {}',
+                    getcwd() . DIRECTORY_SEPARATOR . 'user.php' => '<?php
+                        include("classes.php");
+
+                        new Two();',
+                ],
+                'files_to_check' => [
+                    getcwd() . DIRECTORY_SEPARATOR . 'user.php',
+                ],
+            ],
         ];
     }