prepare-commit-msg.hook

#!/bin/bash
#
# The hook should exit with non-zero status after issuing
# an appropriate message if it wants to stop the commit.

# Strictly disallow uninitialized Variables
set -u
# Exit if a single command breaks and its failure is not handled accordingly
set -e

old_commit_msg="$(cat "${1}")"
echo -n "" > "${1}"

# Check for new or updated PKGBUILDS
# Use the up-to-date .SRCINFO file to retrieve the variables
# shellcheck disable=SC2046
for path in $(dirname $(git diff --name-only --cached) 2>/dev/null | sort -u); do
	if basename -a $(git diff --name-only --cached --diff-filter=A "${path}") 2>/dev/null | sort -u | grep -q "^PKGBUILD$" -; then
		# The PKGBUILD is unknown to git, alter the commit message accordignly
		pkgbase=$(grep "pkgbase = " "${path}/.SRCINFO" | sed 's/^.*= //')
		pkgver=$(grep "pkgver = " "${path}/.SRCINFO" | sed 's/^.*= //')
		pkgrel=$(grep "pkgrel = " "${path}/.SRCINFO" | sed 's/^.*= //')
		echo -e "addpkg: ${pkgbase} ${pkgver}-${pkgrel}" >> "${1}"
	elif basename -a $(git diff --name-only --cached --diff-filter=M "${path}") 2>/dev/null | sort -u | grep -q "^PKGBUILD$" -; then
		# The PKGBUILD is known by git
		pkgbase=$(grep "pkgbase = " "${path}/.SRCINFO" | sed 's/^.*= //')
		pkgver=$(grep "pkgver = " "${path}/.SRCINFO" | sed 's/^.*= //')
		pkgrel=$(grep "pkgrel = " "${path}/.SRCINFO" | sed 's/^.*= //')
		echo -e "upgpkg: ${pkgbase} ${pkgver}-${pkgrel}" >> "${1}"
		## If the pkgrel is "1", assume a new release
		#[[ "${pkgrel}" = "1" && $(type -t pkgver) != "function" ]] && echo -e "new release" >> "${1}"
	fi
done

echo "${old_commit_msg}" >> "${1}"