CSV parser fails with mixed quoting and non-standard row_sep

opts = {row_sep: "|\n", col_sep: ","}
CSV.parse(CSV.generate(opts) { |csv|
  csv << ["yes, it's true"];
  csv << [ "CSV is broken"];
  csv << ["uhoh!"]; }, opts)

In the example above, the parser will raise a CSV::MalformedCSVError (Unquoted fields do not allow new line <"\n"> in line 2.) error.

It will succeed if any of the following are done:

1. pass force_quotes: true to generate
2. add a comma in each row
3. remove the comma from the first row
4. use row_sep: "\n"

Therefore, the problem seems to be that a non-standard row_sep + lines with a field being quoted in one row and unquoted in the next.

Start by reproducing the example with CSV.generate and CSV.parse using row_sep: "|\n", then compare the quoted and unquoted rows against the cases that succeed. Trace how the parser handles row separators and field quoting; done means the mixed-quoting input parses without CSV::MalformedCSVError while the existing alternatives remain valid.