#!/bin/bash

# This script formats the patches from a git branch, adds them

# to the current branch and updates the spec file

# To use it, do e.g.

#

#   $> git checkout master

#   $> git remote add -f fedora-openstack git@github.com:fedora-openstack/nova.git

#   $> git branch master-patches fedora-openstack/master

#   $> ./update-patches.sh

#

# Now your left with a commit which updates the patches

#

# When you've pushed and built the package, don't forget to also

# push the patches with e.g.

#

#   $> git push fedora-openstack +master-patches:master

#

set -e # exit on failure

git status -uno --porcelain | grep . && {

    echo "The repo is not clean. Aborting" >&2

    exit 1

}

filterdiff /dev/null || {

    echo "Please install patchutils" >&2

    exit 1

}

spec=$(fedpkg gimmespec)

branch=$(git branch | awk '/^\* / {print $2}')

patches_branch="${branch}-patches"

patches_base=$(awk -F '=' '/# patches_base/ { print $2 }' "${spec}")

orig_patches=$(awk '/^Patch[0-9][0-9]*:/ { print $2 }' "${spec}")

#

# Create a commit which removes all the patches

#

git rm ${orig_patches}

git commit --allow-empty -m "Updated patches from ${patches_branch}" ${orig_patches}

#

# Check out the ${branch}-patches branch and format the patches

#

git checkout "${patches_branch}"

new_patches=$(git format-patch --no-renames --no-signature -N "${patches_base}")

#

# Filter non dist files from the patches as otherwise

# `patch` will prompt/fail for the non existent files

#

for patch in $new_patches; do

    filterdiff -x '*/.*' $patch > $patch.$$

    mv $patch.$$ $patch

done

#

# Switch back to the original branch and add the patches

#

git checkout "${branch}"

git add ${new_patches}

#

# Remove the Patch/%patch lines from the spec file

#

sed -i '/^\(Patch\|%patch\)[0-9][0-9]*/d' "${spec}"

#

# Add a new set of Patch/%patch lines

#

patches_list=$(mktemp)

patches_apply=$(mktemp)

trap "rm '${patches_list}' '${patches_apply}'" EXIT

i=1;

for p in ${new_patches}; do

    printf "Patch%.4d: %s\n" "${i}" "${p}" >> "${patches_list}"

    printf "%%patch%.4d -p1\n" "${i}" >> "${patches_apply}"

    i=$((i+1))

done

sed -i -e "/# patches_base/ { N; r ${patches_list}" -e "}" "${spec}"

sed -i -e "/%setup -q / { N; r ${patches_apply}" -e "}" "${spec}"

#

# Update the original commit to include the new set of patches

#

git commit --amend -m "Updated patches from ${patches_branch}" "${spec}" ${new_patches}