[git] Git push error '[remote rejected] master -> master (branch is currently checked out)'

git config --local receive.denyCurrentBranch updateInstead

https://github.com/git/git/blob/v2.3.0/Documentation/config.txt#L2155

Use that on the server repository, and it also updates the working tree if no untracked overwrite would happen.

It was added in Git 2.3 as mentioned by VonC in the comments.

I've compiled Git 2.3 and gave it a try. Sample usage:

git init server
cd server
touch a
git add .
git commit -m 0
git config --local receive.denyCurrentBranch updateInstead

cd ..
git clone server local
cd local
touch b
git add .
git commit -m 1
git push origin master:master

cd ../server
ls

Output:

a
b

Yay, b got pushed!