Trac formatting

Herbert Valerio Riedel hvr at
Thu Nov 14 10:11:30 UTC 2013

On 2013-11-13 at 11:36:13 +0100, Simon Marlow wrote:
> On 12/11/13 15:53, Joachim Breitner wrote:
>> Am Dienstag, den 12.11.2013, 15:24 +0000 schrieb Simon Peyton-Jones:
>>> When Trac formats commit messages it is doing a terrible job.  See for
>>> example:
>>> The commit message is nigh illegible until typeset without makup (see
>>> comment 10).
>> I believe it is a feature, not a bug: Trac encourages you to use
>> markdown markup (which supposedly looks good also in plain text) in your
>> commit messages. This not only makes them look nice, provides additional
>> features like automatic linking (compare the reference to #5996 in
>> comment 9 and comment 10).
>> In this case the tables should have been indented by 4 spaces, or
>> surrounded by {{{..}}}, in the commit message to make it come out
>> nicely.
>> Whether this is desirable is a different question. I like it, but the
>> heavy users of the repository and trac need to decide what they prefer –
>> the ability to use markup in the commit messages, or the freedom to do
>> any kind of ascii art.
> I'm with Simon on this one.  I much preferred the old plain-text
> rendering of commit messages.

Luckily, this is an exposed trac.ini setting
(for future reference: changeset.wiki_format_messages)

I've disabled wiki-rendering for commit messages so you can see the
effect. As Joachim already observed, since this is an an all-or-nothing
setting, you lose automatic hyperlinking to Trac tickets, Wiki pages,
other changesets, and even HTTP URLs in every places where commit
messages are rendered.

See for instance,

where you have to manually lookup the ticket-no. as well as the
commit-id of the referenced other commit that this commit tries to
compensate for.

So this undermines one of Trac's principal design goals, that is

    "Trac allows wiki markup in issue descriptions and commit messages,
    creating links and seamless references between bugs, tasks,
    changesets, files and wiki pages."

as is written in the introductory front-page at

> I don't want to start using a particular markup format (which is not
> markdown, it's Trac's own format AIUI) in our commit messages.  What
> happens if we switch from Trac to something else in the future?

It's an unfortunate situation that when Trac came to life around 2005 it
wasn't clear that Markdown would become so popular (and it couldn't have
been used as-is without syntax extensions to allow seamless hyperlinks).

However, if you don't like Trac's Wiki markup and its primary goal of
tight & seamless hyperlinking from everywhere to everywhere, why did you
chose to deploy Trac in the first place? After all, should the GHC
project ever want to switch from Trac to something else, converting the
existing Trac tickets and the GHC Wiki Commentary will be quite an
undertaking retaining the crossrefs as well as stripping out all
Trac-isms... just saying...

PS: Btw, fwiw,


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