Bug #9988: CSV does not write headers when :write_headers is true and no rows are added

• Status: Closed
• Assignee: hsbt (Hiroshi SHIBATA)
• Target version: -
• ruby -v: ruby -v: ruby 2.1.2p95 (2014-05-08 revision 45877) [i386-openbsd]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN

[jeremyevans0 (Jeremy Evans)]

When the CSV :write_headers option is used, headers are only added if at least one row is added:

$ ruby -r csv -e "p CSV.generate(:headers=>%w'a b c', :write_headers=>true){|csv|}"
""
$ ruby -r csv -e "p CSV.generate(:headers=>%w'a b c', :write_headers=>true){|csv| csv << []}"
"a,b,c\n\n"

This seems like a bug to me. It should write the headers even if there are no rows. The attached patch does that:

$ ruby -I lib -r csv -e "p CSV.generate(:headers=>%w'a b c', :write_headers=>true){|csv|}"
"a,b,c\n"

The attached patch should probably be refactored to avoid the duplication, but I think that is best left to the csv maintainer.

[hsbt (Hiroshi SHIBATA)]

• Status changed from Open to Assigned

[hsbt (Hiroshi SHIBATA)]

• Assignee changed from JEG2 (James Gray) to hsbt (Hiroshi SHIBATA)

[hsbt (Hiroshi SHIBATA)]

• Status changed from Assigned to Closed

Applied in changeset trunk|r59640.

---

Fixed to write_headers option behavior when given no rows.

[Bug #9988][ruby-core:63375]