CSV.each rewinding and including header row

[maschwenk]

Reproduction script

require 'csv'

data = CSV.new(<<~ROWS, headers: true)
  Name,Department,Salary
  Bob,Engineering,1000
ROWS

data.each do |row|
  puts row.to_s
end

puts 'second loop'

data.each do |row|
  puts row.to_s
end

ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-darwin18]

ruby csv_bug.rb

Bob,Engineering,1000
second loop
Name,Department,Salary  <--- 🔥this should not be here 🔥 
Bob,Engineering,1000

ruby 2.5.3p105 (2018-10-18 revision 65156) [x86_64-darwin18]

ruby csv_bug.rb

Bob,Engineering,1000
second loop

ruby 2.4.1p111 (2017-03-22 revision 58053) [x86_64-darwin17]

ruby csv_bug.rb

Bob,Engineering,1000
second loop

---

What I think is going on

I may take a crack at fixing myself, but almost certain this isn't desired behavior.

It seems the row pointer is being rewound when calling .each twice, but on the second iteration the rewind is including the header line -- even though I've specified headers: true

Side note, in the future I think .each should always rewind the row counter after execution, which appears what it's trying to do in 2.6.0 but it's accidentally including the header row

---

Side note

Bob should ask for a raise

[kou]

Thanks for your report.
I've fixed this. It means that the second #each doesn't yield anything.

Auto #rewind in each #each isn't good idea. Because CSV provides IO like API. IO doesn't rewind automatically. CSV should not rewind automatically too.