[master] Add a contributing section to README.md

[jesperpedersen]

This pull request adds a contributing section to the README.md file.

The section contains a link to a "Hacking on darktable" wiki page, so that needs to be reviewed together with this pull request.

For "master" branch.

[simonspa]

Hi Jesper,

thanks for that.
One thing I noted when going through the wiki page quickly: the "--rebase" part. The problem with this is that it changes history. So if your branch is public (so pushed to your github repository) and people following this you will break their history.
We discussed this recently - but I don't know the final words on this. Maybe Jeremy can jump in?

/Simon

[jesperpedersen]

Hi Simon,

Yes, it keeps the history linear, since the merge commits are gone - take a look at master in gitk; it is quite complex. It also makes merging two commits for a backport easier. The merge commit gives credit to the committer where it should be the author that is in focus - see https://github.com/jbossas/jboss-as/ as an example.

However, that is the way we do it at work; you guys decide for DT :)

Best regards,
Jesper

[boucman]

so far our discussions tend to go toward a policy of "no rebase on a branch that has been published" the problem is that it changes history, but once published you can't guarentee that it is not left in someone else's history (our "latex" has the problem, it was rebased but there is a github fork that still has it lying around...)

so, no. avoid rebase on public branches

you might want to point to

http://www.darktable.org/redmine/projects/darktable/wiki/Hacking_on_darktable

rather than the page you pointed to...

even better would be to merge these two pages into one as detailed as yours, but following the policies we described above...

could you do that ?

thx
Boucman

[simonspa]

huh? It didn't point there before? I didn't even look at the url since I saw Jepser's wiki page before the pull request...

Beside the rebase thing I'd say: pulling.

[boucman]

my bad, I meant make it point/merge with http://www.darktable.org/redmine/projects/darktable/wiki/Contributing_Code

[boucman]

and I don't think that "credit" for merge commit makes sense... if you want to do who did what you look at the author (not commiter) field of any given commit, you only look at merge commit when they introduce bugs...

[boucman]

Ok, I changed the contributing link to the page we want, everything else is unchanged, thx for that