mscore use libxml2 directly in qt6

mscore.patch

diff --git a/src/importexport/musicxml/CMakeLists.txt b/src/importexport/musicxml/CMakeLists.txt
index f9882fb776..1e06776c65 100644
--- a/src/importexport/musicxml/CMakeLists.txt
+++ b/src/importexport/musicxml/CMakeLists.txt
@@ -19,9 +19,11 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 set(MODULE iex_musicxml)
-
 set(MODULE_QRC musicxml.qrc)
 
+find_package(LibXml2 REQUIRED)
+include_directories("${LIBXML2_INCLUDE_DIRS}")
+
 include(${CMAKE_CURRENT_LIST_DIR}/internal/musicxml/musicxml.cmake)
 
 set(MODULE_SRC
@@ -41,6 +43,7 @@ set(MODULE_SRC
 
 set(MODULE_LINK
     engraving
+    "${LIBXML2_LIBRARIES}"
     )
 
 include(SetupModule)
diff --git a/src/importexport/musicxml/internal/musicxml/importxml.cpp b/src/importexport/musicxml/internal/musicxml/importxml.cpp
index dc41844a54..4e51c36832 100644
--- a/src/importexport/musicxml/internal/musicxml/importxml.cpp
+++ b/src/importexport/musicxml/internal/musicxml/importxml.cpp
@@ -31,6 +31,8 @@
 //#include <QXmlSchemaValidator>
 
 #include "importmxml.h"
+#include <libxml/xmlschemastypes.h>
+#include <libxml/catalog.h>
 #include "musicxmlsupport.h"
 
 #include "translation.h"
@@ -66,44 +68,6 @@ static_assert(int(DurationType::V_BREVE) == int(DurationType::V_LONG) + 1
               && int(DurationType::V_512TH) == int(DurationType::V_256TH) + 1
               && int(DurationType::V_1024TH) == int(DurationType::V_512TH) + 1);
 
-//---------------------------------------------------------
-//   initMusicXmlSchema
-//    return false on error
-//---------------------------------------------------------
-
-//static bool initMusicXmlSchema(QXmlSchema& schema)
-//{
-//    // read the MusicXML schema from the application resources
-//    QFile schemaFile(":/schema/musicxml.xsd");
-//    if (!schemaFile.open(QIODevice::ReadOnly | QIODevice::Text)) {
-//        LOGE("initMusicXmlSchema() could not open resource musicxml.xsd");
-//        return false;
-//    }
-
-//    // copy the schema into a QByteArray and fixup xs:imports,
-//    // using a path to the application resources instead of to www.musicxml.org
-//    // to prevent downloading from the net
-//    QByteArray schemaBa;
-//    QTextStream schemaStream(&schemaFile);
-//    while (!schemaStream.atEnd()) {
-//        QString line = schemaStream.readLine();
-//        if (line.contains("xs:import")) {
-//            line.replace("http://www.musicxml.org/xsd", "qrc:///schema");
-//        }
-//        schemaBa += line.toUtf8();
-//        schemaBa += "\n";
-//    }
-
-//    // load and validate the schema
-//    schema.load(schemaBa);
-//    if (!schema.isValid()) {
-//        LOGE("initMusicXmlSchema() internal error: MusicXML schema is invalid");
-//        return false;
-//    }
-
-//    return true;
-//}
-
 //---------------------------------------------------------
 //   musicXMLValidationErrorDialog
 //---------------------------------------------------------
@@ -114,18 +78,52 @@ static_assert(int(DurationType::V_BREVE) == int(DurationType::V_LONG) + 1
  Return QMessageBox::Yes (try anyway) or QMessageBox::No (don't)
  */
 
-static int musicXMLValidationErrorDialog(QString text, QString detailedText)
+static int musicXMLValidationErrorDialog(void *ctxt,const char *fmt,...)
 {
+	std::string format(fmt);
+	std::string fstr("%s");
+	int count=0;
+	int nPos = format.find(fstr, 0); // fist occurrence
+
+	while (nPos != std::string::npos)
+	{
+		count++;
+		nPos = format.find(fstr, nPos + 1);
+	}
+
     QMessageBox errorDialog;
+	std::va_list argp;
+	va_start(argp, fmt);
+	std::string detailedError;
+	for(int i=0;i<count;i++) {
+	char * t = (char*)malloc(sizeof(char)*4096);
+	t = va_arg(argp, char*);
+	   std::string str(t);
+	   detailedError+=str;
+	   free(t);
+	}
+
+    va_end(argp);
     errorDialog.setIcon(QMessageBox::Question);
-    errorDialog.setText(text);
+    errorDialog.setText("Xml parser error");
     errorDialog.setInformativeText(qtrc("iex_musicxml", "Do you want to try to load this file anyway?"));
-    errorDialog.setDetailedText(detailedText);
+    errorDialog.setDetailedText(QString::fromStdString(detailedError));
     errorDialog.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
     errorDialog.setDefaultButton(QMessageBox::No);
     return errorDialog.exec();
 }
 
+//---------------------------------------------------------
+//   initMusicXmlSchema
+//    return false on error
+//---------------------------------------------------------
+static bool initMusicXmlSchema()
+{
+   xmlSchemaParserCtxtPtr ctxt;
+   ctxt = xmlSchemaNewParserCtxt(QFile(":/schema/musicxml.xsd").fileName().toStdString().c_str());
+   xmlSchemaSetParserErrors(ctxt, (xmlSchemaValidityErrorFunc) musicXMLValidationErrorDialog, (xmlSchemaValidityWarningFunc) musicXMLValidationErrorDialog, ctxt);
+   return (ctxt);
+}
 //---------------------------------------------------------
 //   extractRootfile
 //---------------------------------------------------------
@@ -191,35 +189,62 @@ static bool extractRootfile(QFile* qf, QByteArray& data)
 
 static Err doValidate(const QString& name, QIODevice* dev)
 {
-    NOT_IMPLEMENTED;
-
-    //QElapsedTimer t;
-    //t.start();
-
-    // initialize the schema
-//    ValidatorMessageHandler messageHandler;
-//    QXmlSchema schema;
-//    schema.setMessageHandler(&messageHandler);
-//    if (!initMusicXmlSchema(schema)) {
-//        return Err::FileBadFormat;      // appropriate error message has been printed by initMusicXmlSchema
-//    }
-//    // validate the data
-//    QXmlSchemaValidator validator(schema);
-//    bool valid = validator.validate(dev, QUrl::fromLocalFile(name));
-//    //LOGD("Validation time elapsed: %d ms", t.elapsed());
-
-//    if (!valid) {
-//        LOGD("importMusicXml() file '%s' is not a valid MusicXML file", qPrintable(name));
-//        QString strErr = qtrc("iex_musicxml", "File “%1” is not a valid MusicXML file.").arg(name);
-//        if (MScore::noGui) {
-//            return Err::NoError;         // might as well try anyhow in converter mode
-//        }
-//        if (musicXMLValidationErrorDialog(strErr, messageHandler.getErrors()) != QMessageBox::Yes) {
-//            return Err::UserAbort;
-//        }
-//    }
-
-    return Err::NoError;
+    xmlLoadCatalog("/home/jesper/Hentet/schema/catalog.xml");
+    Err error = Err::UnknownError;
+    xmlDocPtr doc;
+    xmlSchemaPtr schema = NULL;
+    xmlSchemaParserCtxtPtr ctxt;
+    ctxt = xmlSchemaNewParserCtxt("/home/jesper/Hentet/schema/musicxml.xsd");
+    xmlLineNumbersDefault(1);
+
+
+    xmlSchemaSetParserErrors(ctxt, (xmlSchemaValidityErrorFunc) musicXMLValidationErrorDialog, (xmlSchemaValidityWarningFunc) musicXMLValidationErrorDialog,ctxt);
+    schema = xmlSchemaParse(ctxt);
+    xmlSchemaFreeParserCtxt(ctxt);
+
+
+    doc = xmlReadFile(name.toStdString().c_str(), NULL, 0);
+
+       if (doc == NULL)
+        {
+        std::cout << "Could not parse  " <<  name.toStdString() << "\n";
+        }
+    else
+        {
+        xmlSchemaValidCtxtPtr ctxt;
+        int ret;
+
+        ctxt = xmlSchemaNewValidCtxt(schema);
+        xmlSchemaSetValidErrors(ctxt, (xmlSchemaValidityErrorFunc) musicXMLValidationErrorDialog, (xmlSchemaValidityWarningFunc) musicXMLValidationErrorDialog,ctxt);
+        ret = xmlSchemaValidateDoc(ctxt, doc);
+        if (ret == 0)
+            {
+	error =  Err::NoError;
+            }
+        else if (ret > 0)
+         {
+         std::cout <<"fails to validate"<< name.toStdString() << "\n";
+	 error = Err::FileCorrupted;
+        }
+        else
+            {
+         std::cout <<"fails to validate internal error" << "\n";
+	 error = Err::UnknownError;
+
+            }
+        xmlSchemaFreeValidCtxt(ctxt);
+        xmlFreeDoc(doc);
+        }
+
+
+    if(schema != NULL)
+      xmlSchemaFree(schema);
+
+    xmlSchemaCleanupTypes();
+    xmlCleanupParser();
+    xmlMemoryDump();
+
+    return error;
 }
 
 //---------------------------------------------------------