Methods to merge two git repos into one.

merge-repos.sh

# Brings over all tags/branches keeping history intact for the 
# incoming remote data.
$ cd path/to/source-repo
$ git remote add target path/to/target
$ git fetch target --tags 
$ git merge --allow-unrelated-histories target/some-branch
$ git remote remove target

# Or, to merge just the one branch this works but it loses all
# the extra history that the above method preserves.
$ cd path/to/source-repo
$ git remote add target path/to/target
$ git fetch target some-branch:some-branch. # Incoming name should be unique between repos I suspect.
$ git merge --allow-unrelated-histories some-branch
$ git remote remove target
$ git branch -D some-branch