distinguish between absolute geometry files

src/MainWindow.cpp

@@ -765,8 +765,10 @@ bool MainWindow::addPedestrianGroup(int groupID,QString fileName)
         if(! SaxParser::parseGeometryJPS(geometry_file,geometry)) {
             int res = QMessageBox::warning(this, "Errors in Geometry. Continue Parsing?",
                                            "JuPedSim has detected an error in the supplied geometry.\n"
+                                           "<"
+                                           +geometry_file+
+                                           ">"
                                            "The simulation will likely fail using this geometry.\n"
-                                           "Also make sure to validate your file.\n"
                                            "More information are provided in the log file:\n"
                                            +SystemSettings::getLogfile()+
                                            "\n\nShould I try to parse and display what I can?"

src/SaxParser.cpp

@@ -678,16 +678,21 @@ bool SaxParser::parseGeometryJPS(QString fileName, GeometryFactory& geoFac)
      Debug::Messages( "Enter SaxParser::parseGeometryJPS with filename <%s>",fileName.toStdString().c_str());
 
      double captionsColor=0;//red
-     if(!fileName.endsWith(".xml",Qt::CaseInsensitive)) return false;
+     QDir fileDir(fileName);
      QString wd;
      QDir dir(wd);
      SystemSettings::getWorkingDirectory(wd);
-     QString s = dir.relativeFilePath(fileName);
-     fileName=wd + QDir::separator() + s;
+
+     if(!fileName.endsWith(".xml",Qt::CaseInsensitive)) return false;
+     if(!fileDir.isAbsolute())
+     {
+          QString s = dir.relativeFilePath(fileName);
+          fileName=wd + QDir::separator() + s;
+     }
+
      // QString = QDir::cleanPath(wd + QDir::separator() + fileName);
      Debug::Messages("filename: <%s)", fileName.toStdString().c_str());
      Debug::Messages("wd: <%s>",wd.toStdString().c_str());
-
      Building* building = new Building();
      string geometrypath = fileName.toStdString();
      // read the geometry