[mapserver-dev] applying bugfixes to multiple branches

[thomas bonfort]

Hi devs,
Following the workflow described here
http://www.net-snmp.org/wiki/index.php/Git_Workflow,
I've setup a script in our repository that changes the way fixes
should be applied to stable branches. The aim is to simplify the task
of applying a fix to multiple branches. So, in the case where a fix
needs to be applied to more than just master, this is the workflow to
use:

- make sure you have an uptodate clone, and that your master and
stable branches don't have any uncommited or unpushed changes

- pick the oldest branch your fix applies to (or that you are willing
to support), for the example let's say it is branch-5-4

- set your working copy to this branch:
  git checkout branch-5-4

- create a temporary branch for your fix
  git checkout -b bug1234

- code, test your fix, etc...
  git add changd_file.c
  git commit -m "fix bug 1234, blabla"

- once the fix is ready merge it into branch-5-4
  git checkout branch-5-4
  git merge bug1234

- you are now ready to apply this fix in the newer release branches. A
script automates this process:
  sh stablemerge.sh

- what the script does is iteratively merge 4-10 into 5-0, then 5-0
into 5-2, etc, up till 6-0 into master. This means your fix is
propagated to all newer branches down into master.

- for more complex fixes and/or very old branches, the fix will likely
not always apply cleanly from one branch to the next. You'll be
returned back to your shell with a message indicating which file has a
conflict and asked to manually edit it to resolve. Once you've fixed
the conflict, commit your edited file, and rerun the stablemerge.sh
script to continue propagating your updated fix to newer branches.

Please try to avoid copy-pasting a fix in multiple branches to
accomplish the same task, as it will result in conflicts the next time
someone runs the process.

Don't hesitate to ping me if you need help with this.

best regards,

thomas