#80 -fix does not work as documented

[Samuel Messner]

I have a PNG with the only error being an incorrect CRC in the PLTE chunk, and when I run pngcrush -fix -ow on it, the CRC does not get fixed. Instead, I just get a familiar libpng error:

While measuring IDATs in test.png pngcrush caught libpng error:
   [00][00][00][00]: CRC error

  Recompressing IDAT chunks in test.png
   Total length of data found in critical chunks            =         0

I've attached the image I'm getting the error with. Have a look if you've got the time!