bug#19021: Possible bug in sort

[Ben Mendis]

http://stackoverflow.com/questions/26869717/why-does-sort-seem-to-sort-a-field-incorrectly-based-on-the-presence-or-absenc

Data is here: https://gist.github.com/anonymous/2a7beb4871b25ae8f8b3

This results in line 7 being sorted incorrectly: sort -t , -k 1n < weird.csv

This produced the expected results: cut -f , -d 1-3 < weird.csv | sort -t ,
-k 1n

Using 'g' instead of 'n' also produces the expected results, but I'm not
clear on what the difference is between 'g' and 'n'.

Tested with sort 8.21 on Slackware64-current.