Created attachment 59719 [details]
file with 82140 bytes on one line
Opening a file where data on one line exceeds 64KB data the result is truncated, even if contents of each single field are less than 64k characters, which currently is the internal limit of cell content.
Eike Rathke committed a patch related to this issue.
It has been pushed to "master":
resolved fdo#48501 enable line size >64k in SvStream::Read*Line()