From 1813411ca9f9b60e62ef70e8be2e169af0831edb Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Wed, 2 Nov 2022 10:53:24 +0100
Subject: [PATCH 03/28] schemas: Fix infinite loop in
 xmlSchemaCheckElemSubstGroup

Types like xmlSchemaTypeAnyTypeDef have a base type pointing to itself,
resulting in an infinite loop.

Fixes #430.

Reference: https://github.com/GNOME/libxml2/commit/abb5a93fed95cfd628db72e9e1a51fc3ced5c941
Conflict: NA
---
 xmlschemas.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xmlschemas.c b/xmlschemas.c
index 9aa6acf..4a767ac 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -19957,7 +19957,8 @@ xmlSchemaCheckElemSubstGroup(xmlSchemaParserCtxtPtr ctxt,
 	    /*
 	    * The set of all {derivation method}s involved in the derivation
 	    */
-	    while ((type != NULL) && (type != headType)) {
+	    while ((type != NULL) && (type != headType) &&
+                   (type != type->baseType)) {
 		if ((WXS_IS_EXTENSION(type)) &&
 		    ((methSet & XML_SCHEMAS_TYPE_BLOCK_RESTRICTION) == 0))
 		    methSet |= XML_SCHEMAS_TYPE_BLOCK_EXTENSION;
-- 
2.27.0