From ae169c9cbe7a4eb45dac11183c9e6c8045377ccf Mon Sep 17 00:00:00 2001
From: AndrolGenhald <AndrolGenhald@gmail.com>
Date: Tue, 14 Dec 2021 17:07:49 -0600
Subject: [PATCH] Check for indirect circular dependencies with stubbed
 parents.

---
 src/Psalm/Internal/Codebase/Populator.php     | 32 ++++++++++++-------
 tests/StubTest.php                            |  4 +--
 .../fixtures/stubs/CircularReference.phpstub  |  2 ++
 3 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/src/Psalm/Internal/Codebase/Populator.php b/src/Psalm/Internal/Codebase/Populator.php
index 136dad383af..a09e538b465 100644
--- a/src/Psalm/Internal/Codebase/Populator.php
+++ b/src/Psalm/Internal/Codebase/Populator.php
@@ -19,8 +19,10 @@
 use function array_intersect_key;
 use function array_keys;
 use function array_merge;
+use function array_splice;
 use function count;
 use function in_array;
+use function key;
 use function reset;
 use function strlen;
 use function strpos;
@@ -293,18 +295,26 @@ private function populateClassLikeStorage(ClassLikeStorage $storage, array $depe
 
         if (isset($this->invalid_class_storages[$fq_classlike_name_lc])) {
             foreach ($this->invalid_class_storages[$fq_classlike_name_lc] as $dependency) {
-                if (isset($dependency->dependent_classlikes[$fq_classlike_name_lc])) {
-                    if ($dependency->location) {
-                        IssueBuffer::maybeAdd(
-                            new CircularReference(
-                                'Circular reference discovered when loading ' . $dependency->name,
-                                $dependency->location
-                            )
-                        );
-                    }
+                // Dependencies may not be fully set yet, so we have to loop through dependencies of dependencies
+                $dependencies = [strtolower($dependency->name) => true];
+                do {
+                    $current_dependency_name = key(array_splice($dependencies, 0, 1)); // Key shift
+                    $current_dependency = $storage_provider->get($current_dependency_name);
+                    $dependencies += $current_dependency->dependent_classlikes;
+
+                    if (isset($current_dependency->dependent_classlikes[$fq_classlike_name_lc])) {
+                        if ($dependency->location) {
+                            IssueBuffer::maybeAdd(
+                                new CircularReference(
+                                    'Circular reference discovered when loading ' . $dependency->name,
+                                    $dependency->location
+                                )
+                            );
+                        }
 
-                    continue;
-                }
+                        continue 2;
+                    }
+                } while (!empty($dependencies));
 
                 $dependency->populated = false;
                 unset($dependency->invalid_dependencies[$fq_classlike_name_lc]);
diff --git a/tests/StubTest.php b/tests/StubTest.php
index cb513ee7f79..199205f1f6a 100644
--- a/tests/StubTest.php
+++ b/tests/StubTest.php
@@ -280,9 +280,7 @@ public function testStubFileCircularReference(): void
         $this->addFile(
             $file_path,
             '<?php
-                class Foo extends Bar
-                {
-                }
+                class Foo extends Baz {}
             '
         );
 
diff --git a/tests/fixtures/stubs/CircularReference.phpstub b/tests/fixtures/stubs/CircularReference.phpstub
index 5f4002edd62..7eadeb4e26e 100644
--- a/tests/fixtures/stubs/CircularReference.phpstub
+++ b/tests/fixtures/stubs/CircularReference.phpstub
@@ -1,3 +1,5 @@
 <?php
 
 class Bar extends Foo {}
+
+class Baz extends Bar {}