From be8217368b85ab078905e17a732965053f3443d6 Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikita.ppv@gmail.com>
Date: Thu, 23 Sep 2021 12:44:51 +0200
Subject: [PATCH] Bail on exception during delayed autoload

We shouldn't try to load further classes if one autoload throws.

This fixes oss-fuzz #38881, though I believe there are still two
deeper issues here: 1) Why do we allow autoloading with an active
exception? 2) Exception save & restore should probably also save
and restore the exception opline.
---
 Zend/tests/exception_during_variance_autoload.phpt | 31 ++++++++++++++++++++++
 Zend/zend_inheritance.c                            |  3 +++
 2 files changed, 34 insertions(+)
 create mode 100644 Zend/tests/exception_during_variance_autoload.phpt

diff --git a/Zend/tests/exception_during_variance_autoload.phpt b/Zend/tests/exception_during_variance_autoload.phpt
new file mode 100644
index 0000000..995931d
--- /dev/null
+++ b/Zend/tests/exception_during_variance_autoload.phpt
@@ -0,0 +1,31 @@
+--TEST--
+Exception during delayed variance autoload
+--FILE--
+<?php
+spl_autoload_register(function($class) {
+    echo "$class\n";
+    if ($class == 'X') {
+        new Y;
+    }
+    if ($class == 'Y') {
+        new Q;
+    }
+});
+class A {
+    function method(): X {}
+}
+class B extends A {
+    function method(): Y {}
+}
+?>
+--EXPECTF--
+Y
+Q
+
+Warning: Uncaught Error: Class "Q" not found in %s:%d
+Stack trace:
+#0 %s(%d): {closure}('Y')
+#1 {main}
+  thrown in %s on line %d
+
+Fatal error: Could not check compatibility between B::method(): Y and A::method(): X, because class Y is not available in %s on line %d
diff --git a/Zend/zend_inheritance.c b/Zend/zend_inheritance.c
index b00c5e5..33869d6 100644
--- a/Zend/zend_inheritance.c
+++ b/Zend/zend_inheritance.c
@@ -2348,6 +2348,9 @@ static void load_delayed_classes() {
 
 	ZEND_HASH_FOREACH_STR_KEY(delayed_autoloads, name) {
 		zend_lookup_class(name);
+		if (EG(exception)) {
+			break;
+		}
 	} ZEND_HASH_FOREACH_END();
 
 	zend_hash_destroy(delayed_autoloads);
-- 
1.8.3.1