[Rd] "deparse" with "nlines" argument produces empty elements (PR#13299)

[kbarton at zbs.bialowieza.pl]

Full_Name: Kamil Bartoñ
Version: 2.8.0
OS: windows xp
Submission from: (NULL) (212.33.92.187)


According to the "deparse" function documentation "nlines" is the *maximum*
number of lines to produce. But, when "nlines" argument is supplied, it produces
exactly nlines of result, and the result contains empty elements at the end.

Example:

> deparse(quote(foo(1,2,3)), width.cutoff = 20, nlines=7)
[1] "foo(1, 2, 3)" ""             ""             ""             ""            
""             ""           

This behavior affects e.g. output of warnings() where "..." is attached to every
call rather than only the truncated ones.

> warnings()
Warning messages:
1: In plot.window(...) ... : "na.action" is not a graphical parameter