From 1bad176b2496579d760852c80cff3ad9fb7c3a4b Mon Sep 17 00:00:00 2001
From: Adrian Perez de Castro <aperez@igalia.com>
Date: Mon, 20 Nov 2023 07:42:30 -0800
Subject: [PATCH] Build fails with libxml2 version 2.12.0 due to API change
 https://bugs.webkit.org/show_bug.cgi?id=265128

Reviewed by Philippe Normand.

Starting with libxml2 2.12.0, the API has changed the const-ness of the
xmlError pointers, which results in a build error due to a mismatched
type in the parsing error callback. This papers over the difference by
using preprocessor conditionals.

* Source/WebCore/xml/XSLTProcessor.h: Use const when building against
  libxml2 2.12.0 or newer.
* Source/WebCore/xml/XSLTProcessorLibxslt.cpp:
(WebCore::XSLTProcessor::parseErrorFunc): Ditto.

Canonical link: https://commits.webkit.org/270977@main

Conflit: NA
Reference: https://github.com/WebKit/WebKit/commit/1bad176b2496579d760852c80cff3ad9fb7c3a4b
---
 Source/WebCore/xml/XSLTProcessor.h          | 4 ++++
 Source/WebCore/xml/XSLTProcessorLibxslt.cpp | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/Source/WebCore/xml/XSLTProcessor.h b/Source/WebCore/xml/XSLTProcessor.h
index 21bb45b5cbe1..5cf20557918f 100644
--- a/Source/WebCore/xml/XSLTProcessor.h
+++ b/Source/WebCore/xml/XSLTProcessor.h
@@ -61,7 +61,11 @@ class XSLTProcessor : public RefCounted<XSLTProcessor> {
 
     void reset();
 
+#if LIBXML_VERSION >= 21200
+    static void parseErrorFunc(void* userData, const xmlError*);
+#else
     static void parseErrorFunc(void* userData, xmlError*);
+#endif
     static void genericErrorFunc(void* userData, const char* msg, ...);
     
     // Only for libXSLT callbacks
diff --git a/Source/WebCore/xml/XSLTProcessorLibxslt.cpp b/Source/WebCore/xml/XSLTProcessorLibxslt.cpp
index a65691087e3c..9f6b363dfc6c 100644
--- a/Source/WebCore/xml/XSLTProcessorLibxslt.cpp
+++ b/Source/WebCore/xml/XSLTProcessorLibxslt.cpp
@@ -59,7 +59,11 @@ void XSLTProcessor::genericErrorFunc(void*, const char*, ...)
     // It would be nice to do something with this error message.
 }
 
+#if LIBXML_VERSION >= 21200
+void XSLTProcessor::parseErrorFunc(void* userData, const xmlError* error)
+#else
 void XSLTProcessor::parseErrorFunc(void* userData, xmlError* error)
+#endif
 {
     PageConsoleClient* console = static_cast<PageConsoleClient*>(userData);
     if (!console)