Utf-8 is the default encoding in Qt6 anyway

src/core/symbology/qgsstyle.cpp

@@ -212,7 +212,9 @@ bool QgsStyle::saveSymbol( const QString &name, QgsSymbol *symbol, bool favorite
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   symEl.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO symbol VALUES (NULL, '%q', '%q', %d);",
                                        name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
@@ -411,7 +413,9 @@ bool QgsStyle::saveColorRamp( const QString &name, QgsColorRamp *ramp, bool favo
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   rampEl.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO colorramp VALUES (NULL, '%q', '%q', %d);",
                                        name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
@@ -961,7 +965,9 @@ bool QgsStyle::saveTextFormat( const QString &name, const QgsTextFormat &format,
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   formatElem.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO textformat VALUES (NULL, '%q', '%q', %d);",
                                        name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
@@ -1035,7 +1041,9 @@ bool QgsStyle::saveLabelSettings( const QString &name, const QgsPalLayerSettings
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   settingsElem.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO labelsettings VALUES (NULL, '%q', '%q', %d);",
                                        name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
@@ -1104,7 +1112,9 @@ bool QgsStyle::saveLegendPatchShape( const QString &name, const QgsLegendPatchSh
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   shapeElem.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO legendpatchshapes VALUES (NULL, '%q', '%q', %d);",
                                        name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
@@ -1222,7 +1232,9 @@ bool QgsStyle::saveSymbol3D( const QString &name, QgsAbstract3DSymbol *symbol, b
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   elem.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO symbol3d VALUES (NULL, '%q', '%q', %d);",
                                        name.toUtf8().constData(), xmlArray.constData(), ( favorite ? 1 : 0 ) );
@@ -2280,7 +2292,9 @@ int QgsStyle::addSmartgroup( const QString &name, const QString &op, const QStri
 
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
   smartEl.save( stream, 4 );
   QString query = qgs_sqlite3_mprintf( "INSERT INTO smartgroup VALUES (NULL, '%q', '%q')",
                                        name.toUtf8().constData(), xmlArray.constData() );
@@ -2665,7 +2679,9 @@ bool QgsStyle::exportXml( const QString &filename )
   }
 
   QTextStream ts( &f );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   ts.setCodec( "UTF-8" );
+#endif
   doc.save( ts, 2 );
   f.close();
 
@@ -3038,7 +3054,9 @@ bool QgsStyle::updateSymbol( StyleEntity type, const QString &name )
   QDomElement symEl;
   QByteArray xmlArray;
   QTextStream stream( &xmlArray );
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
   stream.setCodec( "UTF-8" );
+#endif
 
   QString query;