git rebase --abort of an --onto run does not checkout the originating branch

'git rebase --abort' has documentation stating it will restore the 
original <branch>.  This works great for my basic usage of 'git rebase 
--interactive', for instance.

When running 'git rebase --onto', it does exactly what the documentation 
states, but the restored branch is not desirable.

To cherry pick a range of commits, I run:

git rebase --onto mybranch START_SHA END_SHA

In the middle, I decide to run 'git rebase --abort'.

Just as the documentation states, it performs a checkout of END_SHA as 
the restored branch.  END_SHA has nothing to do with the originating 
branch, and confusion ensues.

Is there a reason why 'git rebase' should not store off the originating 
branch and use that for an --abort, instead of <branch> which is END_SHA?

Thanks.

Josh