When doing 'mvn release:prepare' with a Git provider, a 'git push' command is executed. This is not ideal because the push command can fail or push things from the local repository that are not needed/wanted in the remote repository. Some examples are:
1. The local repository has two branches: master (tracking origin/master) and dummy (tracking origin/dummy). The release is being made on the master branch, and the dummy and origin/dummy branches have diverged. Running 'release:prepare' causes a 'git push', which will succeed for the master branch (assuming that the release preparation has been made correctly) and fail for the dummy branch (the two branches have diverged and need to be merged or rebased). The release preparation aborts and the directory is left in a somewhat inconsistent state where manual cleaning up is needed (removing pom.xml.next files, changing versions to <new>-SNAPSHOT, etc.)
2. The local repository has two branches: master (tracking origin/master) and localtest (not in the origin repository). The localtest branch shouldn't be published because it is just used for some temporary testing and doesn't even work. It will be pushed during 'release:prepare'.
Suggested behaviour: use 'git push origin <currentbranch>:<currentbranch>', or even better, query for which remote repository to push to (found in .git/config) and which branch to push from and to. For me, it would be great to have a 'confirm push' before doing it so as to keep things clean, but maybe that is quite complex.