[ptx] nona cannot render a single image

[Chris]

Hi,

if I make a project, contains only one single image,
set pixel dimensions, and press Stitch (render),
nona says:

FATAL: 09:56:01.576990 (NonaStitcherPanel.cpp:338) Stitch(): (): error during stitching:
Precondition violation!
basicImage::upperLeft(): image must have non-zero size.
(../foreign/vigra/basicimage.hxx:631)

but PTStitcher works in this case flawlessly. Is it a nona bug?

thx,
Chris