Code page setting in the manifest has no effect on pre-Windows10. So, the application still works well except it cannot read/write files that have special characters in their names. Fortunately for us, Microsoft took on the task of migrating users to current Windows versions, so we don’t need to worry about supporting earlier versions.
Thanks for your efforts. Since UTF-8 is not the default code page on Windows applications yet, your changes are still useful, as they make things a bit simpler for VTK users. Maybe in a couple of years, when UTF-8 will become the default code page on Windows and then we don’t need to use a custom compatibility layer anymore (similarly to how vtkStdString served its time and is now ready to be retired).
Has everything been merged into VTK master? I still see lots of plain fopen in VTK master.