I have a single job configured to build all branches of a git repo and poll for changes, and I have been experiencing a bug with build triggering.

Steps to reproduce

1. Create a new repo locally and run these in the repo:

   touch somefile.txt
   git commit -m "Add a file" somefile.txt
   

2. Create a new repo on github
3. Create a Jenkins job with this configuration:
   • Set 'Repository URL' to the new github repo
   • Set 'Branches to build' to '**'
   • Check 'Prune remote branches before build', 'Skip internal tag', 'Clean after checkout', 'Recursively update submodules', 'Wipe out workspace before build'
   • Check 'Poll SCM'
   • Set 'Schedule' to '* * * * *'
   • Add the following shell script as a build step:

     echo $GIT_BRANCH

4. Push the master branch of your local repo to github
5. Wait for Jenkins build (build #1)
6. Run these in your local repo:

   git checkout -b feature master
   echo stuff > somefile.txt
   git commit -m "Some changes" somefile.txt
   git push origin feature
   

7. Wait for Jenkins build (build #2)
8. Run these in your local repo:

   git checkout master
   git merge feature
   git push origin master
   

What happens

After step 5, build #1 prints 'origin/master'. After step 7, build #2 prints 'origin/feature'. After step 8, nothing happens in Jenkins.

What should happen

Builds #1 and #2 are fine. There should be a build #3 after step 8 which prints 'origin/master'.