Re: Bazaar workflow for GRUB

[Colin Watson <cjwatson@ubuntu.com>]

On Mon, Jan 18, 2010 at 09:49:15AM -0800, Colin D Bennett wrote:
> Do you want to mention how GRUB committers should merge features to the
> official trunk branch?  I think the appropriate process, assuming
> (1) either a merge directive or a feature branch provides the change
> the we want to merge, and (2) we already have a local mirror branch of
> GRUB's trunk branch:
> 
>   # 1. Update local trunk mirror.
>   cd trunk
>   bzr pull
> 
>   # 2. Merge the feature branch or merge directive.
>   bzr merge URL_OF_BRANCH
>   # (Or bzr merge /path/to/merge_directive.patch)
>   # If there are conflicts reported, fix them and use “bzr resolve” to
>   # mark them as resolved.
>   [ make grub ... and test it ]
> 
>   # 3. Commit the change locally.
>   bzr commit
> 
>   # 4. Push to the upstream trunk.
>   bzr push :parent
>   #   (The :parent argument can be omitted after the first time you do
>   #   this, since Bazaar will remember the given location from that
>   #   point on as the “push location” for the local branch.)
>   # Note that in the unlikely event that someone happened to commit to
>   # upstream trunk in the meantime since you did “bzr pull”, Bazaar
>   # will tell you that the branches have diverged.  You should try
>   # again, doing “bzr pull --overwrite” and go back to step 2.

I recommend using a checkout for trunk, because that way bzr takes out a
write lock on the branch when you start committing and doesn't release
it until it's finished; it also warns you immediately if you're out of
date rather than making you commit and try to push before you find out.
This is a much more robust workflow for shared branches in my
experience.

The workflow for a trunk checkout, based on what you have above, is
simply:

  # 1. Update local trunk checkout.
  cd trunk
  bzr update

  # 2. Merge the feature branch or merge directive.
  bzr merge URL_OF_BRANCH
  # (Or bzr merge /path/to/merge_directive.patch)
  # If there are conflicts reported, fix them and use “bzr resolve” to
  # mark them as resolved.
  [ make grub ... and test it ]

  # 3. Commit the change.
  bzr commit
  # If someone happened to commit to upstream trunk since you did “bzr
  # update”, Bazaar will tell you that you need to update again.

-- 
Colin Watson                                       [cjwatson@ubuntu.com]