Can't parse a single new line character

[cbeer]

$ ruby -r csv -e 'puts CSV::VERSION'
3.0.1
$ ruby -v
ruby 2.6.0rc1 (2018-12-06 trunk 66253) [x86_64-darwin18]

This seems to be a recent regression.

In Ruby 2.6:

> CSV.parse("\n", {headers:'s'}) { |x| puts x }
Traceback (most recent call last):
       11: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/bin/irb:23:in `<main>'
       10: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/bin/irb:23:in `load'
        9: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/gems/2.6.0/gems/irb-0.9.6/exe/irb:11:in `<top (required)>'
        8: from (irb):5
        7: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv.rb:693:in `parse'
        6: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv.rb:1147:in `each'
        5: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv.rb:1205:in `shift'
        4: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv.rb:1205:in `loop'
        3: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv.rb:1239:in `block in shift'
        2: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv.rb:1239:in `new'
        1: from /Users/cabeer/.rubies/ruby-2.6.0-rc1/lib/ruby/2.6.0/csv/row.rb:32:in `initialize'
NoMethodError (undefined method `each' for nil:NilClass)

In Ruby 2.5:

CSV.parse("\n", {headers:'s'}) { |x| puts x }

=> nil

[kou]

Thanks for your report.
I've fixed this.