Compile to existing pdf file


I have noticed this several times now, and is still present in Beta 020.

When I compile a piece of my project on its own pdf file, nothing happens if the file is open in a reader, even in Win7 Explorer window.

Nothing gives me an information that the file cannot be overwritten.

I’m prompted to overwrite, but when I open the pdf file, it has still as many pages as before.

And it is only selected in Windows explorer, with the viewer panel open…

Could there be a dialog telling when compile function will not proceed?