For 3rdparty package maintainers looking to port a patched package forward to a new rosdistro here's what William did to port BFL forward into indigo from hydro. 

Tully

On Thu, May 1, 2014 at 1:04 AM, Michael Ferguson <mfergs7@gmail.com> wrote:

Wow! Easy indeed!

Thanks for going ahead and cranking that out -- I would have never figured that out. I agree, copying that to the mailing list would probably be helpful to anyone who ends up maintaining one of these kind of packages down the road.

-Fergs

On Thu, May 1, 2014 at 1:01 AM, William Woodall <wjwwood@gmail.com> wrote:

I went ahead and did it, this is what I did:

$ git clone https://github.com/ros-gbp/bfl-release.git

$ cd bfl-release

$ git checkout master

$ cp -r hydro indigo

$ git add indigo

$ git commit -m "create indigo patch folder with indigo package.xml template"

$ git-bloom-config copy hydro indigo

$ git-bloom-config edit indigo

... change settings for indigo

... change rosdistro to indigo

... change patches directory to indigo

$ bloom-release -r indigo -t indigo bfl

... give it the release repo: https://github.com/ros-gbp/bfl-release.git

... push with force if needed for tags

... push changes but don't open pull request

$ cd ..

$ rm -rf bfl-release

$ git clone https://github.com/ros-gbp/bfl-release.git

$ cd bfl-release

$ python -c "from bloom.git import track_branches; track_branches()"

... This tracks all remote branches locally

$ git branch

... go to each indigo patch branch and copy over any patches from the hydro equivalents

... probably just need patches/release/.../bfl and patches/debian/.../bfl

... for instance:

$ git ls-tree --name-only -r patches/release/hydro/bfl | grep '\.patch' | xargs -I {} sh -c 'git show patches/release/hydro/bfl:"$1" > "$1"' -- {}

$ git add ./*.patch

$ git commit -m "migrating patches from hydro"

$ git push origin patches/release/indigo/bfl

... Once you have migrated any patches you need, bloom-release and pull request

$ bloom-release -r indigo -t indigo bfl

... give it the release repo: https://github.com/ros-gbp/bfl-release.git

https://github.com/ros/rosdistro/pull/4079

And "it's that easy"! :)

Unfortunately this is pretty tedious and error prone and not well documented, but it should only affect a handful of cases and I've often considered a tool to help with this, but always shied away from it because I think the cost out weighs the benefit.

We can copy this to ros-release as well.