Git push branch from one remote to another?

I've found this one:

git push rorg 'refs/remotes/korg/*:refs/heads/*'

And it pushed all my remote branches from korg to rorg (even without local copies of the branches). See the output below:

Counting objects: 293, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (67/67), done.
Writing objects: 100% (176/176), 48.32 KiB, done.
Total 176 (delta 105), reused 168 (delta 97)
remote: Resolving deltas:  11% (12/105)
To <<MY_REPOSITORY_URL>>
 * [new branch]      korg/gingerbread-> gingerbread
 * [new branch]      korg/gingerbread-release -> gingerbread-release
 * [new branch]      korg/honeycomb-> honeycomb
 * [new branch]      korg/HEAD -> HEAD
 * [new branch]      korg/honeycomb-mr1-release-> honeycomb-mr1-release
 * [new branch]      korg/master -> master

And then you can make the same push for tags refs:

git push rorg 'refs/tags/*:refs/tags/*'

A quick test making some temporary repositories shows you can construct a refspec that can do this:

$ git push rorg origin/one:refs/heads/one
Counting objects: 5, done.
Writing objects: 100% (3/3), 240 bytes, done.
Total 3 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (3/3), done.
To /tmp/rorg
 * [new branch]      origin/one -> one

So origin/BRANCHNAME:refs/heads/BRANCHNAME

Checking in my rorg remote:

pat@host /tmp/rorg (BARE:master)
$ git graph --all
* 5750bca (HEAD, master) c
| * 13fd55a (one) b
|/
* 822e0de a

To complement patthoyt's answer, here's a short shell script that pushes all the branches from one remote to another:

SRC_REMOTE=korg
DST_REMOTE=rorg
for a in $(git branch --list --remote "$SRC_REMOTE/*" | grep -v --regexp='->')
  do git push "$DST_REMOTE" "$a:refs/heads/${a//$SRC_REMOTE\/}"
done

To summarize, for each remote branch on the source remote (excluding "pointer" branches like HEAD), push that ref to the destination remote. (The ${a//$SRC_REMOTE\/} bit strips the source remote name from the branch name, i.e., origin/master becomes master.)

This works in Zsh

Notice the single quote is necessary to prevent unexpected parameter expansion in some cases.

git push rorg 'refs/remotes/korg/*:refs/heads/*'