abuild: Warn if -doc subpackage exceeds a certain threshold

In the warning, suggest splitting the -doc subpackage into additional
smaller packages (which are not pulled in by the `docs` meta package).

Fixes https://gitlab.alpinelinux.org/alpine/tsc/-/issues/16

APKBUILD.5.scd

@@ -215,6 +215,11 @@ file.
 		packages containing firmware, and should typically never
 		be needed.
 
+	*bigdocs*
+		Specifies that this packages intentionally has a large -doc subpackage.
+		Thereby suppressing a warning to be emitted if the -doc subpackage
+		exceeds a certain package size threshold (currently 2 MiB).
+
 	*charset.alias*
 		Specifies that the package ships a _/usr/lib/charset.alias_
 		file and that it should be installed on the user's

abuild.in

@@ -32,6 +32,7 @@ fi
 : ${SETFATTR:="setfattr"}
 
 apk_opt_wait="--wait 30"
+doc_threshold=$((2 * 1024 * 1024)) # 2 MiB
 
 umask 022
 
@@ -1764,14 +1765,19 @@ create_apks() {
 		local dir="${file%/.PKGINFO}"
 		local name=$(pkginfo_val pkgname "$file")
 		local ver=$(pkginfo_val pkgver "$file")
-		local size=$(pkginfo_val size "$file" | human_size)
+		local size=$(pkginfo_val size "$file")
 		local apk=$name-$ver.apk
 		local datadir="$pkgbasedir"/$name
 		local subpkgname=$name
 		local subpkgarch=$(pkginfo_val arch "$file")
 
+		# See https://gitlab.alpinelinux.org/alpine/tsc/-/issues/16
+		if ! options_has "bigdocs" && is_doc_pkg "$name" && [ "$size" -gt "$doc_threshold" ]; then
+			warning "The -doc subpackage is unusually large, consider splitting it"
+		fi
+
 		trace_apk_deps "$name" "$dir" "$subpkgarch" || return 1
-		msg "Package size: ${size}"
+		msg "Package size: $(echo "$size" | human_size)"
 		msg "Compressing data..."
 		(
 		cd "$datadir"

tests/abuild_test

@@ -23,6 +23,8 @@ init_tests \
 	abuild_invalid_pkgnames \
 	abuild_invalid_subpkgnames \
 	abuild_invalid_subpkg_version \
+	abuild_large_doc_subpackage \
+	abuild_bigdocs \
 	abuild_warn_pkgver_patch_version \
 	abuild_multiline_license \
 	abuild_git_ceiling \
@@ -441,6 +443,24 @@ abuild_invalid_subpkg_version_body() {
 		abuild all
 }
 
+abuild_large_doc_subpackage_body() {
+	init_keys
+	cp -ra "$testrepo"/large-doc-subpkg .
+	cd large-doc-subpkg
+	atf_check -s exit:0 \
+		-e match:"-doc subpackage is unusually large" \
+		abuild all
+}
+
+abuild_bigdocs_body() {
+	init_keys
+	cp -ra "$testrepo"/large-doc-subpkg .
+	cd large-doc-subpkg
+	options=bigdocs atf_check -s exit:0 \
+		-e not-match:"-doc subpackage is unusually large" \
+		abuild all
+}
+
 abuild_warn_pkgver_patch_version_body() {
 	cp -ra "$testrepo"/test-pkgname .
 	cd test-pkgname

tests/testrepo/large-doc-subpkg/APKBUILD

@@ -0,0 +1,35 @@
+# Maintainer: Natanael Copa <ncopa@alpinelinux.org>
+
+# test package
+pkgname="large-doc-subpkg"
+pkgver="1.0"
+pkgrel=0
+pkgdesc="Dummy test package to check if large doc subpackages cause a warning to be emitted"
+url="https://gitlab.alpinelinux.org/alpine/aports"
+arch="noarch"
+license="MIT"
+subpackages="$pkgname-doc"
+source=""
+
+prepare() {
+	mkdir -p "$builddir"
+}
+
+build() {
+	true
+}
+
+check() {
+	true
+}
+
+package() {
+	mkdir -p "$pkgdir/usr/bin"
+	cat >"$pkgdir/usr/bin/foo" <<EOF
+	#!/bin/sh
+EOF
+
+	mkdir -p "$pkgdir/usr/share/doc/$pkgname"
+	dd bs=1024 count=$((3 * 1024)) if=/dev/random \
+		of="$pkgdir/usr/share/doc/$pkgname/large-file"
+}