Question

After editing my old question a few times, I make a new one because it is a new question now.

In .git/hooks/post-update I have:

echo "a" >> /home/pi/log
git update-server-info
git stash
git merge testing >> /home/pi/log

To make an automated checkout. So I run on the client:

git push testing HEAD:testing

Now my /home/pi/log contains:

a
Updating ae2f44b..04753a9
Fast-forward
 application/views/main/index.php |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

But the file did not change!

$ git merge testing
Already up-to-date.

If I remove the script, make the push and run git stash, git merge testing it works.

Update

For testing I changed a number in a file from 17 to 20. I can see the right file version if I run

git show application/views/main/index.php

but

vim application/views/main/index.php

Still contains the old number. But git claims the file is updated:

$ git merge testing
Already up-to-date.

Answer 1

The solution is to use post-receive as Alex pointed out. Also you need run unset GIT_DIR at the top of your script.

On the server I have created a second branch and switched to it:

$ git branch
  master
* testing

My .git/hooks/post-receive now looks like this:

unset GIT_DIR
cd ..
git merge master

On the client I run git push.