Empty filename passed to function

[carbolymer]

After invocation of the following command:

$ qnapi -c -l Pl Supernatural.S13E02.720p.HDTV.X264-DIMENSION\[rarbg\].mkv 
QNapi 0.2.3, http://qnapi.github.io
Qt version: 5.10.1

 * Downloading subtitles for 'Supernatural.S13E02.720p.HDTV.X264-DIMENSION[rarbg].mkv'
   Calculating checksums...
   Searching for subtitles [pl] (NapiProjekt)...
   Downloading subtitles...
   Unpacking subtitles...
   Post-processing subtitles file...
   Adjusting subtitles...
Empty filename passed to function
Empty filename passed to function
Empty filename passed to function
Empty filename passed to function
Empty filename passed to function
Empty filename passed to function

QNapi usually returns few Empty filename passed to function lines - I don't know if this is a bug, but signals abnormal application behaviour.