Fix #18532

qgisapp.cpp

  while ( featureIt != features.constEnd() )
  {
    QgsAttributes srcAttr = featureIt->attributes();
    QgsAttributeMap dstAttr;

    for ( int src = 0; src < srcAttr.count(); ++src )
    {
      int dst = remap.value( src, -1 );
      if ( dst < 0 )
        continue;
      
      QVariant srcValue = srcAttr.at( src );
      int type = pasteVectorLayer->fields().field( dst ).type();
      if srcValue->canConvert( type )
        srcValue->convert( type );

      dstAttr[ dst ] = srcValue;
}