Saving rotated (90/270 degree) jpeg images aborts the app with a "Bogus virtual array access" message printed on the stdout. This is happening, because libjpeg 7 and up requires properly filling jpeg_width/jpeg_height before transforming the image.
The code fixing this is available at https://github.com/ksztyber/gpicview.git, commit ID 811943b7a8400b653bb21744da5e55e66f401cef.