Am Mittwoch, 5. September 2018 schrieb Stefan Krusche:
> Good day everyone,
>
> is anybody using digikam to edit images? I encountered this bug recently,
> that digikam fails with an only general error message "Failed to save file"
> when I try to save an image file in PNG format. It is reproducible like
> this:
>
> 1. start digikam
> 2. open any image to edit
> 3. save as: select PNG file
> --> failure
>
> Exspected behavior:
> 3. save as: should save the converted to PNG format image file
>
> Other formats seem to work well, I have tried .jpg, .jp2
>
> In ~/.xsession-errors there are some message which may be related:
>
> Opening the image file into the editor:
> TQFile::open: No file name specified
> TQFile::open: No file name specified
> Exif Qt::Orientation: 1
>
> Saving:
> TQFile::open: No file name specified
> TQFile::open: No file name specified
> JPEG image preview size: (1280 x 720) pixels - 80124 bytes
> libpng error: known incorrect sRGB profile
> digikam: WARNING: error saving image
> '/home/user/xyz/lnw39a.digikamtempfile.tmp
>
> This tmp file is created with zero size and vanishes after clicking ok in
> the dialog with the error message.
>
> Searching the greatest database of all ages taught me that the libpng error
> message is commonly known and that something had been changed in handling
> PNG format which I don't understand really, but my guess is that the
> interaction of digikam with libpng might be affected.
>
> System information:
> TDE R14.0.5 (PSB)
> digikam 0.9.6 using PNG library version 1.6.28
> Devuan ascii
>
> Before I try to find out more and/or create a bug report I'd like to ask if
> anyone has seen this error and knows what to do about it. Any ideas and
> hints welcome.
>
> Kind regards,
> Stefan

Additional information:
- original image file is in JPG format as downloaded from my phone
- there is another libpng warning in between the actions in ~/.xsession-errors:
  "libpng warning: iCCP: known incorrect sRGB profile"