hook.sh

grahamc@Morbo> cat .git/hooks/pre-push                                                                               ~/projects/nixpkgs
#!/nix/store/qp5fw57d38bd1n07ss4zxh88zg67c3vg-bash-4.4-p12/bin/bash
#
# This hook is called with the following parameters:
#
# $1 -- Name of the remote to which the push is being done
# $2 -- URL to which the push is being done
#
# If pushing without using a named remote those arguments will be equal.

PATH="/nix/store/vp8y0rh8rq7vikbbrpf28jfym79xq9z8-coreutils-8.28/bin:/nix/store/la2d2akppv70g8xd1d8vhd53iqskin9r-git-2.14.3/bin"

set -eu

remote="$1"
url="$2"

z40=0000000000000000000000000000000000000000

pass() {
    echo "@";
    exit 0
}

fail() {
    echo "$@";
    exit 1
}

debug() {
    if [ "x${SAFE_MODE:-x}" != "xx" ]; then
        echo "DEBUG: $@" >&2
    fi
}

debug "Inputs:"
debug " remote=$remote"
debug " url=$url"

if [ "x${SAFE_MODE:-x}" != "xx" ]; then
    debug "Enabling safe-mode because SAFE_MODE is set"
else
    # Don't push new branches to NixOS/Nixpkgs
    case "$url" in
        *NixOS/nixpkgs.git)
            debug "Safe mode activated."
            ;;
        *)
            debug "$url doesn't appear to be upstream, go wild"
            exit 0
    esac
fi


while read local_ref local_sha remote_ref remote_sha
do
    debug "Handling:"
    debug " local_ref=$local_ref"
    debug " local_sha=$local_sha"
    debug " remote_ref=$remote_ref"
    debug " remote_sha=$remote_sha"
    if [ "$local_sha" = $z40 ]
    then
        case "$remote_ref" in
            'refs/heads/master')
                fail "Refusing to delete master"
                ;;
            refs/heads/release-*)
                fail "Don't delete releases!"
                ;;
            *)
                pass "Delete permitted by fall-through"
                ;;
        esac
    else
	if [ "$remote_sha" = $z40 ]
	then
            fail "Don't create new branches upstream"
	else
	    # Update to existing branch, examine new commits
	    range="$remote_sha..$local_sha"

	    # Check for WIP commit
	    commits=`git rev-list "$range"`
            count=$(echo "$commits" | wc -l)
            if [ "$count" -gt 1 ]; then
                git log "$range"
                echo "-----------------------------------"
                echo "You tried to push ${count} commits."
                echo "Please review the above diff, and if you still"
                echo "want to push, run git push with --no-verify"
                fail
            fi
        fi
    fi
done