abuild: add an option to keep all directories

This is mainly needed for alpine-baselayout which creates all
directories, and most of them are empty. The code in question
would remove directories we explicitly want alpine-baselayout
to create and own.

abuild.in

@@ -1788,12 +1788,14 @@ human_size() {
 create_apks() {
 	local file= dir= name= ver= apk= datadir= size=
 	local gzip=$(command -v pigz || echo gzip)
+	if ! options_has "keepdirs"; then
 		rmdir "$pkgdir"/usr/lib \
 			"$pkgdir"/usr/bin \
 			"$pkgdir"/usr/share \
 			"$pkgdir"/usr \
 			"$pkgdir"/etc/ \
 			2>/dev/null || :
+	fi
 	if ! options_has "!tracedeps"; then
 		for file in "$pkgbasedir"/.control.*/.PKGINFO; do
 			dir="${file%/.PKGINFO}"

tests/abuild_test

@@ -32,6 +32,7 @@ init_tests \
 	abuild_git_ceiling \
 	abuild_package_size_zero \
 	abuild_package_size_nonzero \
+	abuild_keepdirs \
 	abuild_amove \
 	abuild_doc \
 	abuild_dev \
@@ -619,6 +620,32 @@ abuild_package_size_nonzero_body() {
 		cat pkg/.control.test-size/.PKGINFO
 }
 
+abuild_keepdirs_body() {
+	init_keys
+	mkdir -p test-amove
+
+	cd test-amove
+	cat > APKBUILD <<-EOF
+		# Maintainer: Test User 123 <123@example.com>
+
+		# test package
+		pkgname="test-keepdirs"
+		pkgver="1.0"
+		pkgrel=0
+		pkgdesc='Dummy test package - keepdirs'
+		url='https://gitlab.alpinelinux.org/alpine/aports'
+		arch='noarch'
+		license='MIT'
+		options='keepdirs'
+
+		package() {
+			mkdir -p "\$pkgdir"/usr/bin
+		}
+	EOF
+	abuild rootpkg || atf_fail "abuild rootpkg failed"
+	test -d pkg/test-keepdirs/usr/bin || atf_fail "$i failed"
+}
+
 abuild_amove_body() {
 	init_keys
 	mkdir -p test-amove