Not disputing whether its a bug or not, however..
With it set to 1 line confirmation:
"a" is of course, 1 line, regardless of crlf or not
"a<crlf>" is still 1 line because theres nothing after crlf and thus nothing to send.
With it set to 2 line confirmation:
"a" is still 1 line.
"a<crlf>" is still 1 line.
"a<crlf><crlf>" would be classed as 2 because the 2nd crlf would be on a new line.
Eamonn.