Right now, if you call number_to_currency(-1.23), it will return "$-1.23". This is not correct in most cases. It should be "-$1.23" and it should allow for other negative formats like "($1.23)".
I made a ticket for this and submitted a patch with more information: https://rails.lighthouseapp.com/projects/8994/tickets/5894-number_to_currency-doesnt-format-negative-numbers-correctly
Any codereviews or feedback would be appreciated.