Duplicate check when filing new tickets

A new duplicate ticket is a new ticket that has been posted before. For the background into the issues surrounding new duplicate tickets, see the following discussions:

• ​NewTicket duplicates discussion
• ​ticket duplicate discussion
• #MostFrequentDuplicatesPlugin proposal
• ​DuplicateTicketSearchPlugin on trac-hacks

Good implementations of checking new duplicate tickets are:

• ​Ubuntu LaunchPad. See screenshots below.
• ​Stackoverflow. After you type in a question, the area immediately below the title (summary, in Trac) is populated with a list of questions that possibly match based on the text. This would fit into the existing Trac UI fairly easily.

Display an overview, and two links "report bug", "ask question"

Show frequently reported bugs, and allow enter title

Display possible duplicates, and allow enter bug, or notify security team

MostFrequentDuplicatesPlugin

Here is an idea for a plugin that could be used for doing semi-automated duplicate checking. It is a more automated version of what is described in the MostFrequentDuplicates page, by using the information collected there before new tickets get created.

We could use a bit more structure in that page, for associating patterns to tickets. Examples:

Pattern

HTMLParseError: bad end tag

Duplicate of

#4365

Note

related to a SilverCity bug

Pattern

PyGIT.py.*cannot concatenate 'str' and 'NoneType' objects

Duplicate of

#6976

Note

This is a bug in the ​TH:GitPlugin for Trac on nonexistent paths, see ​TH:ticket:2671

Before ticket creation, the ticket description is scanned for the available (multi-line) patterns and if a match is found, a validation warning should be returned (see tags/trac-0.11/trac/ticket/api.py@#L127​). This will prevent ticket creation and show a warning which can display the duplicate ticket and the associated note. See also the InterWiki​ module for hints about retrieving data from a Wiki page.