New L4 project with clean history

l4project.sh

# Initial setup
git clone -o framework -b develop https://github.com/laravel/laravel.git project-name
cd project-name
git checkout --orphan master
git commit -m "Initial commit"

# Pulling changes
git fetch framework
git merge --squash -m "Upgrade Laravel" framework/develop
# Fix merge conflicts if any and commit

Thanks for this @akuzemchak. I adapted this to work with Laravel setups that have already been worked on and not cloned in the beginning from the Laravel repo. If you don't want to update from the master branch, be sure to change the third line.

git remote add framework [email protected]:laravel/laravel
git fetch framework
git merge --squash -m "Upgrade Laravel" framework/master
# Alternatively, specify a version tag by doing
# git merge --squash -m "Upgrade Laravel" v4.0.5

# Fix conflicts if any
git mergetool
git commit -m "Upgrade Laravel"

# Clean up any files left by fixing conflicts (they shouldn't be tracked at any point).
git clean -n # Make sure everything is correct!
git clean -f

Just a quick note on doing the same now that laravel is stable, since you're cloning the master branch now you won't be able to run git checkout --orphan master because there's already a branch named master so the steps I take now are:

# Initial setup
git clone -o framework https://github.com/laravel/laravel.git project-name
cd project-name

# Rename pulled master branch
git branch -m master laravel

git checkout --orphan master
git commit -m "Initial commit"

# Pulling changes
git fetch framework
git merge --squash -m "Upgrade Laravel" framework/master
# Fix merge conflicts if any and commit

I think you can even delete the laravel branch but I'm not sure. Hope it helps.