Trac Ticket Conditional Validate Fields Plugin
This plugin will validate fields based on the ticket type. This plugin is similar to TracTicketValidatorPlugin with the addition of being able to validate different fields depending on the ticket type.
If you have any issues, create a new ticket.
Download the zipped source from here.
Install this plugin as per the usual installation procedure and apply the following to the trac.ini file:
[ticket_validate] defect = comment, summary enhancement = summary comment.rule = .* comment.tip = Please input comment summary.rule = [A-Z].* summary.tip = Please correct summary