app-arch/gzip: Support app-alternatives/gzip

Signed-off-by: Michał Górny <mgorny@gentoo.org>

app-arch/gzip/gzip-1.12-r3.ebuild

@@ -0,0 +1,84 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+VERIFY_SIG_OPENPGP_KEY_PATH="${BROOT}"/usr/share/openpgp-keys/gzip.asc
+inherit flag-o-matic verify-sig
+
+DESCRIPTION="Standard GNU compressor"
+HOMEPAGE="https://www.gnu.org/software/gzip/"
+SRC_URI="mirror://gnu/gzip/${P}.tar.xz
+	https://alpha.gnu.org/gnu/gzip/${P}.tar.xz"
+SRC_URI+=" verify-sig? (
+		mirror://gnu/gzip/${P}.tar.xz.sig
+		https://alpha.gnu.org/gnu/gzip/${P}.tar.xz.sig
+	)"
+
+LICENSE="GPL-3+"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~x64-cygwin ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris"
+IUSE="pic static"
+
+BDEPEND="verify-sig? ( sec-keys/openpgp-keys-gzip )"
+RDEPEND="!app-arch/pigz[symlink(-)]"
+PDEPEND="
+	app-alternatives/gzip
+"
+
+PATCHES=(
+	"${FILESDIR}/${PN}-1.3.8-install-symlinks.patch"
+)
+
+src_configure() {
+	use static && append-flags -static
+
+	# Avoid text relocation in gzip
+	use pic && export DEFS="NO_ASM"
+
+	# bug #663928
+	econf --disable-gcc-warnings
+}
+
+src_install() {
+	default
+
+	docinto txt
+	dodoc algorithm.doc gzip.doc
+
+	# Avoid conflict with app-arch/ncompress
+	rm "${ED}"/usr/bin/uncompress || die
+
+	# keep most things in /usr, just the fun stuff in /
+	# also rename them to avoid conflict with app-alternatives/gzip
+	dodir /bin
+	local x
+	for x in gunzip gzip zcat; do
+		mv "${ED}/usr/bin/${x}" "${ED}/bin/${x}-reference" || die
+	done
+	sed -i -e 's:exec gzip:&-reference:' \
+		"${ED}"/bin/{gunzip,zcat}-reference || die
+	mv "${ED}"/usr/share/man/man1/gzip{,-reference}.1 || die
+	rm "${ED}"/usr/share/man/man1/{gunzip,zcat}.1 || die
+}
+
+pkg_postinst() {
+	if [[ -n ${REPLACING_VERSIONS} ]]; then
+		local ver
+		for ver in ${REPLACING_VERSIONS}; do
+			if ver_test "${ver}" -lt "1.12-r2"; then
+				ewarn "This package no longer installs 'uncompress'."
+				ewarn "Please use 'gzip -d' to decompress .Z files."
+			fi
+		done
+	fi
+
+	# ensure to preserve the symlinks before app-alternatives/gzip
+	# is installed
+	local x
+	for x in gunzip gzip zcat; do
+		if [[ ! -h ${EROOT}/bin/${x} ]]; then
+			ln -s "${x}-reference" "${EROOT}/bin/${x}" || die
+		fi
+	done
+}