+ fixes #0002297: 'Export to PDF...' from drawing view does not show an error if existing file can not be overwritten

src/Mod/Drawing/Gui/DrawingView.cpp

@@ -593,6 +593,13 @@ void DrawingView::print(QPrinter* printer)
     }
 
     QPainter p(printer);
+    if (!p.isActive() && !printer->outputFileName().isEmpty()) {
+        qApp->setOverrideCursor(Qt::ArrowCursor);
+        QMessageBox::critical(this, tr("Opening file failed"),
+            tr("Can't open file '%1' for writing.").arg(printer->outputFileName()));
+        qApp->restoreOverrideCursor();
+        return;
+    }
     QRect rect = printer->paperRect();
 #ifdef Q_OS_WIN32
     // On Windows the preview looks broken when using paperRect as render area.