The windows that let you type in file names need to warn
you when the input method is not the default.  Otherwise,
it is possible to go to a non-standard input method
to put some special characters into a diagram,
and leave it turned on when you type a file name.
The file name then ends up with unintended 8-bit characters.

It would probably be best if all windows relating to filenames
had their own choice of input method.  Failing that, a little
notice saying "Input Method=IPA" would be good.

Hi,

dia upstream and I agree that this is a GTK+ issue. Feel free to handle
appropriately and/or close the bug as appropriate.

Thanks,

bye,
  Roland