Force push from a Jenkins job seems like a very dangerous option.

Can you describe further why you want a Jenkins job to be able to delete history from a repository?

The Jenkins plugin can merge, and can push that merge result, so long as no intervening commit has been pushed to the destination branch in the central repository. If an intervening commit has been pushed to the destination branch, then the Jenkins job is not allowed to push the merge result because it would overwrite the intervening commit with that forced push.

Yes, of course force push is really dangerous.

But in our case it's needed, for example, we are using https://gemfury.com/ service.
With this we can push code to be build directly with git: http://devcenter.gemfury.com/articles/git-push-package.html

But, as we have to always push on remote master branch, it's needed to force push.

For example:
we have 2 current branch for our software 2.4 and master (future 3.0).
we are pushing master to master for building 3.0.0-dev version and then push --force 2.4 to master for building 2.4.0-dev.

It's really awesome.

I already have a wroking branch here: https://github.com/guilhem/git-plugin/tree/forceOption
Just need to fix credentials :/ (don't know how to do...)

Here is a PR https://github.com/jenkinsci/git-plugin/pull/248

Here's our use case:

We have multiple jobs for feature branches. Often somebody wants to push their changes to have them built by Jenkins, but not yet merged/pushed to team/release branch. Instead of removing the push configuration from the job (and having to add it again afterwards, very error prone), we separate the job in 2 jobs: 1 build job and 1 push job. The developers can then disable/enable the push job at will.

The build job merges with bugfix/current-release/next-release branches, and pushes that merge commit (after a successful build) to a temporary branch <jenkins/feature-branch>. The push job then pushes that to the next-release branch. If that merge commit doesn't make it to next-release branch (push job was disabled, or someone else pushed to next-release branch first), that merge commit is essentially useless. The next run the build job creates a new merge commit, but can't push to <jenkins/feature-branch> because the new merge commit is non-fast-forward to the old commit. We need a force push to overwrite the old commit on the temporary branch

Code changed in jenkins
User: Wannes Sels
Path:
src/test/java/hudson/plugins/git/GitPublisherTest.java
http://jenkins-ci.org/commit/git-plugin/b14f6f4398c0ccfb88392dfda8baaf2ef9e3a2c8
Log:
added testcase for force push JENKINS-24082

Code changed in jenkins
User: Guilhem Lettron
Path:
src/test/java/hudson/plugins/git/GitPublisherTest.java
http://jenkins-ci.org/commit/git-plugin/ef6bc1856202a8d7a936ce881b083517bc1e28a3
Log:
Merge pull request #1 from wannessels/forceOption

added testcase for force push JENKINS-24082

Code changed in jenkins
User: Wannes Sels
Path:
src/main/java/hudson/plugins/git/GitPublisher.java
src/main/resources/hudson/plugins/git/GitPublisher/config.jelly
src/test/java/hudson/plugins/git/GitPublisherTest.java
http://jenkins-ci.org/commit/git-plugin/cebb9da131fa6c9e07ec9e6ff71ec89aa58fdd6f
Log:
Merge pull request #248 from guilhem/forceOption

[FIXED JENKINS-24082] Add a force option to push command

Compare: https://github.com/jenkinsci/git-plugin/compare/adc96942cd67...cebb9da131fa

Code changed in jenkins
User: Wannes Sels
Path:
src/test/java/hudson/plugins/git/GitPublisherTest.java
http://jenkins-ci.org/commit/git-plugin/db14f9f5659794a146ee4850e7f63795f6b10e77
Log:
fixed GitPublisherTest.testForcePush , was not deterministic JENKINS-24082

Fixed in git plugin 2.2.6, released 20 Sep 2014