view CONTRIBUTING @ 41720:6704696141b8

templates: adding a config() function for template customization

This allows templates to be written such that users can customize them easily,
or that they can be customized based on other configuration of the system.  For
enterprise deployments, we often have complex template aliases, and right now
the only way individual users can customize those is by replacing the whole
template alias (which means they won't get company-wide updates to it anymore,
plus most users don't want to have to get a complex template right).
With this change, they can just set a config option which feeds into our
templates for common changes (e.g. whether to limit commit descriptions to the
width of their terminal or not).

To work around the issue of having to register the config options, I declared
a dedicated section [templateconfig] for these options to be dynamically
declared. They can still reference any other config option that's registered
elsewhere.

I only did string, bool and int at this time - list and date would add other
complications with parsing the default so I'll leave that as an exercise to
the reader :)

Differential Revision: https://phab.mercurial-scm.org/D5959

Our full contribution guidelines are in our wiki, please see:

https://www.mercurial-scm.org/wiki/ContributingChanges

If you just want a checklist to follow, you can go straight to

https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist

If you can't run the entire testsuite for some reason (it can be
difficult on Windows), please at least run `contrib/check-code.py` on
any files you've modified and run `python contrib/check-commit` on any
commits you've made (for example, `python contrib/check-commit
273ce12ad8f1` will report some style violations on a very old commit).