#!/bin/bash

set -e

changeid=$(sed 's/^Change-Id: \(I.*\)$/\1/;t;d' $1)
# let git do its own if there's no change-id
[ "$changeid" = "" ] && exit 0

commit=$(sed 's/^From.*\([0-9a-fA-F]\{40\}\).*/\1/;t;d' $1)
# must have a commit ID - if this fails git changed
[ "$commit" == "" ] && exit 2

commit=${commit:0:12}

date=$(date +%Y%m%d%H%M%S)

# remove change-id
sed 's/^Change-Id: I.*$//;T;d' -i $1
# and add message-id
sed "s/^From: /Message-Id: <$date.$commit.$changeid@changeid>\nFrom: /" -i $1