view CONTRIBUTING @ 31996:e6e1884df298

track-tags: write all tag changes to a file

The tag changes information we compute is now written to disk. This gives
hooks full access to that data.

The format picked for that file uses a 2 characters prefix for the action:

    -R: tag removed
    +A: tag added
    -M: tag moved (old value)
    +M: tag moved (new value)

This format allows hooks to easily select the line that matters to them without
having to post process the file too much. Here is a couple of examples:

 * to select all newly tagged changeset, match "^+",
 * to detect tag move, match "^.M",
 * to detect tag deletion, match "-R".

Once again we rely on the fact the tag tests run through all possible
situations to test this change.

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).