https://bugs.gentoo.org/918973
https://gitlab.gnome.org/GNOME/libxslt/-/issues/99
https://gitlab.gnome.org/GNOME/libxslt/-/commit/86ec392efd75ce24b79f4baa9822a1b088f3e47f

From 86ec392efd75ce24b79f4baa9822a1b088f3e47f Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Fri, 1 Dec 2023 21:05:19 +0100
Subject: [PATCH] tests: Fix build with older libxml2

Fixes #99.
--- a/tests/runtest.c
+++ b/tests/runtest.c
@@ -456,7 +456,8 @@ initializeLibxml2(void) {
     xmlSetExternalEntityLoader(xmlNoNetExternalEntityLoader);
     xmlSetGenericErrorFunc(NULL, testErrorHandler);
     xsltSetGenericErrorFunc(NULL, testErrorHandler);
-    xmlSetStructuredErrorFunc(NULL, testStructuredErrorHandler);
+    xmlSetStructuredErrorFunc(NULL,
+            (xmlStructuredErrorFunc) testStructuredErrorHandler);
     exsltRegisterAll();
     xsltRegisterTestModule();
     xsltMaxDepth = 200;
-- 
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