abuild: warn when p in pkgver should be _p

we have for example had sudo 1.9.5p2 which should have been
1.9.5_p2. Show a warning to avoid this in the future.

abuild.in

@@ -197,6 +197,10 @@ default_sanitycheck() {
 	# give 0 as it is always valid and give the pkgrel
 	$APK version --check --quiet 0-r"$pkgrel" || \
 		die "$pkgrel is not a valid pkgrel"
+	# warn when p1 should be _p1
+	case "$pkgver" in
+		*[0-9]p[0-9]) warning "pkgver should probably be $(echo "$pkgver" | sed -E -e 's/(.*[0-9])p([0-9])/\1_p\2/')";;
+	esac
 	[ -z "$pkgdesc" ] && die "Missing pkgdesc in APKBUILD"
 	[ -z "$url" ] && die "Missing url in APKBUILD"
 	[ -z "$license" ] && die "Missing license in APKBUILD"

tests/abuild_test

@@ -21,6 +21,7 @@ init_tests \
 	abuild_invalid_pkgnames \
 	abuild_invalid_subpkgnames \
 	abuild_invalid_subpkg_version \
+	abuild_warn_pkgver_patch_version \
 	abuild_multiline_license \
 	abuild_git_ceiling \
 	abuild_package_size_zero \
@@ -414,6 +415,17 @@ abuild_invalid_subpkg_version_body() {
 		abuild all
 }
 
+abuild_warn_pkgver_patch_version_body() {
+	cp -ra "$testrepo"/test-pkgname .
+	cd test-pkgname
+	TESTPKGVER=1.0_p1 atf_check -s exit:0 \
+		-e not-match:'WARNING' \
+		abuild sanitycheck
+	TESTPKGVER=1.0p1 atf_check -s exit:0 \
+		-e match:'WARNING.*1.0_p1' \
+		abuild sanitycheck
+}
+
 abuild_multiline_license_body() {
 	cp -ra "$testrepo"/test-licenses .
 	cd test-licenses

tests/testrepo/test-pkgname/APKBUILD

@@ -2,7 +2,7 @@
 
 # test package
 pkgname=${TESTNAME-test-pkgname}
-pkgver="1.0"
+pkgver="${TESTPKGVER-1.0}"
 pkgrel=0
 pkgdesc="Dummy test package that fails to build"
 url="https://gitlab.alpinelinux.org/alpine/aports"