"Stopped reading at empty line" warning in fread should not appear if sep and nrows args specified

[richierocks]

If I explicitly specify the sep and nrows arguments in a call to fread, then it means I typically have a non-standard file format that contains a section of delimited file + plus some other metadata or junk.

In this case, it is common (at least for me) for the data portion to be in the middle, with extra content afterwards. That means that I frequently receive the erroneous warning

Stopped reading at empty line 123 but text exists afterwards (discarded)

I don't want to suppressWarnings since I could miss other, genuine warnings.

It would be really useful if fread assumed that by specifying both the sep and nrows arguments, the user knows that they aren't necessarily going to read to the end of the file, and that this warning is not shown.