prevent-bad-push.hook

#!/bin/bash
# Based on the pre-push sample generated by default in .git/hooks
# Source: https://www.git-scm.com/docs/githooks/1.7.1
#
# Prevents push of commits where the log message starts
# with "WIP" (work in progress). Called by "git push" after
# it has checked the remote status, but before anything has been pushed.
#
# The hook should exit with non-zero status after issuing an appropriate
# message if it stops the push.
#
# Requirements: 
#   * Bash
#
# To enable this hook, rename this file to "pre-push".

# 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.
#
# Information about the commits which are being pushed is supplied as lines to
# the standard input in the form:
#
#   <local ref> <local sha1> <remote ref> <remote sha1>

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

z40=0000000000000000000000000000000000000000

while read local_ref local_sha remote_ref remote_sha
do
	if [ "$local_sha" = $z40 ]
	then
		# Handle delete
		:
	else
		if [ "$remote_sha" = $z40 ]
		then
			# New branch, examine all commits
			range="$local_sha"
		else
			# Update to existing branch, examine new commits
			range="$remote_sha..$local_sha"
		fi

		# Check for WIP commit
		commit=`git rev-list -n 1 --grep '^WIP' "$range"`
		if [ -n "$commit" ]
		then
			echo >&2 "Found WIP commit in $local_ref, not pushing"
			exit 1
		fi
	fi
done

exit 0