Get a git-svn clone faster if someone else has already cloned

git-svn-clone-from-existing-clone.sh

#!/bin/bash
# @arg 1 - the git repository on someone elses machine or a server
#   ie. [email protected]:/home/gmcgregor/MODULE_NAME
# @arg 2 - the svn url to point to
#   ie. https://svn.my-company.com/MODULE_NAME

# check if required programs are installed
type svn >/dev/null 2>&1 || { echo >&2 "svn needs to be installed for this script to run."; exit 1; }
type git >/dev/null 2>&1 || { echo >&2 "git needs to be installed for this script to run."; exit 1; }
git svn --help >/dev/null 2>&1 || { echo >&2 "git-svn needs to be installed for this script to run."; exit 1; }

GIT_VERSION=$( git --version | sed 's/.*\([0-9]\.[0-9]\.[0-9]\)/\1/' | sed 's/\.//g' )
if [ $GIT_VERSION -ge  200 ]; then 
    REMOTE_PREFIX="origin/"
else
    REMOTE_PREFIX=""
fi

# check args
args_err="Requires 2 arguments
@arg 1 - the git repository on someone elses machine or a server
@arg 2 - the svn url to point to
"
if [ $# -ne 2 ]; then
    echo >&2 "$args_err"
    exit 1
fi

git ls-remote $1 >/dev/null 2>&1 || { echo >&2 "Not a valid git repo."; exit 1; }
svn list $2 >/dev/null 2>&1 || { echo >&2 "Not a valid svn url."; exit 1; }

# Clone locally - make sure the refs/remotes/ space matches the server
folder=${1%.git*}
folder=${folder%/}
folder=${folder##*/}
if [ -e $folder ]; then
    echo >&2 "$folder already exists. Aborting."
    exit 1
fi
mkdir $folder
cd $folder
git init
git remote add origin $1
git config --replace-all remote.origin.fetch '+refs/remotes/${REMOTE_PREFIX}*:refs/remotes/${REMOTE_PREFIX}*'
git fetch
# Prevent fetch/pull from remote git server in the future,
# we only want to use git svn for future updates
git config --remove-section remote.origin
# check the svn remote if standard layout
svn list $2 | grep "trunk/" -q
if [ $? -eq 0 ]; then
    git svn init --stdlayout $2
    remote_branch="remotes/${REMOTE_PREFIX}trunk"
else
    git svn init $2
    remote_branch="remotes/${REMOTE_PREFIX}git-svn"
fi
# Create branch master and  point to trunk
git checkout -b master $remote_branch
# Git version 1.9.x doesn't support setting an upstream branch
if $(echo $GIT_VERSION | grep '^19' -q) ; then
    git branch --set-upstream-to=$remote_branch
fi
# Pull the latest changes from Subversion
git svn fetch
git rebase $remote_branch
# if .gitignore does not exist, create it
if [[ ! -e .gitignore ]]; then
    echo "# Migrated from svn:ignore" > .gitignore
    git svn show-ignore >> .gitignore
fi

cd ..