readstat_get_row_count returns -1 for xport

[andreasnoack]

It's being set in

ReadStat/src/sas/readstat_xport_read.c

Line 259 in 69f5518

.row_count = -1,

. Is it because the value isn't directly available in the file header? If so then it would be great to document the meaning of -1. I couldn't find any explanations for the value. From the source, it looks like it's parsed_row_count which is counting the number of rows as you go.

[evanmiller]

Yes - -1 is intended as a sentinel value to indicate that the row count is not available in the file metadata. Happy to add a comment to the header file to this effect.