pgm with long comment lines are not read correctly

I'm using gwenview to visualize pgm which works fine; unless there are long comment lines in the file.

Reproducible: Always

Steps to Reproduce:
1. putIf you put the following data in a pgm file (eg KO.pgm):

P5
# this is a very long comment line that make sure that gwenview will not be able to visualize me (123456789012345678901234567890)
1 1
255
2

2. try to open it: gwenview KO.pgm

Actual Results:
error: "Loading 'KO.pgm' failed"

Expected Results:
gwenview showing pgm

you can do the same steps but with the next data; and gwenview will show no error. It is the long comment that is producing the problem.

P5
# this is a short comment line
1 1
255
2

This is the output of "gwenview --version":
Qt: 4.8.5
KDE Development Platform: 4.11.5
Gwenview: 4.11.4