dev-db/mysql-connector-c: Use res_n* functions only on GLIBC

The issue occurs because the package tries to use the res_n* functions
(specifically res_ninit, res_nsearch and res_nclose) from resolv.h which
do not exist when using musl. So we are falling back to non-thread-safe
functions from resolv.h

Closes: https://bugs.gentoo.org/761352
Signed-off-by: brahmajit das <brahmajit.xyz@gmail.com>
Closes: https://github.com/gentoo/gentoo/pull/26353
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 172 insertions, 0 deletions

diff --git a/dev-db/mysql-connector-c/files/mysql-connector-c-8.0.27-res_n.patch b/dev-db/mysql-connector-c/files/mysql-connector-c-8.0.27-res_n.patch
new file mode 100644
index 000000000000..34961b8ad9e2
--- /dev/null
+++ b/dev-db/mysql-connector-c/files/mysql-connector-c-8.0.27-res_n.patch
@@ -0,0 +1,49 @@
+# Musl doesn't have res_n* functions so we are falling back to the not
+# thread safe ones. Patch made with help from developer Fabian Groffen
+# <grobian@gentoo.org>.
+#
+# Closes: https://bugs.gentoo.org/761352
+# See also: https://github.com/mysql/mysql-server/pull/385
+# See also: https://bugs.mysql.com/bug.php?id=106034
+--- a/libmysql/CMakeLists.txt
++++ b/libmysql/CMakeLists.txt
+@@ -423,6 +423,19 @@ IF(HAS_WARN_FLAG)
+     )
+ ENDIF()
+
++check_symbol_exists(res_ninit "resolv.h" HAVE_RES_NINIT_FUNCTION)
++check_symbol_exists(res_nsearch "resolv.h" HAVE_RES_NSEARCH_FUNCTION)
++check_symbol_exists(res_nclose "resolv.h" HAVE_RES_NCLOSE_FUNCTION)
++IF (HAVE_RES_NINIT_FUNCTION)
++	add_compile_definitions(HAVE_RES_NINIT)
++ENDIF(HAVE_RES_NINIT_FUNCTION)
++IF (HAVE_RES_NSEARCH_FUNCTION)
++	add_compile_definitions(HAVE_RES_NSEARCH)
++ENDIF(HAVE_RES_NSEARCH_FUNCTION)
++IF (HAVE_RES_NCLOSE_FUNCTION)
++	add_compile_definitions(HAVE_RES_NCLOSE)
++ENDIF(HAVE_RES_NCLOSE_FUNCTION)
++
+ # Verify that libmysql_api_test runs OK
+ ADD_CUSTOM_COMMAND(TARGET libmysql_api_test POST_BUILD
+   COMMAND libmysql_api_test
+--- a/libmysql/dns_srv.cc
++++ b/libmysql/dns_srv.cc
+@@ -37,6 +37,17 @@
+ #include <netdb.h>
+ #include <resolv.h>
+
++/* we don't have anything else but the non-thread-safe variants */
++#if !defined(HAVE_RES_NINIT)
++#define res_ninit(X)              (void)X
++#endif
++#if !defined(HAVE_RES_NSEARCH)
++#define res_nsearch(X,D,I,S,B,L)  res_search(D,I,S,B,L)
++#endif
++#if !defined(HAVE_RES_NCLOSE)
++#define res_nclose(X)             (void)X
++#endif
++
+ // POSIX version
+
+ static bool get_dns_srv(Dns_srv_data &data, const char *dnsname, int &error) {
diff --git a/dev-db/mysql-connector-c/mysql-connector-c-8.0.27-r1.ebuild b/dev-db/mysql-connector-c/mysql-connector-c-8.0.27-r1.ebuild
new file mode 100644
index 000000000000..7058ba6c50ed
--- /dev/null
+++ b/dev-db/mysql-connector-c/mysql-connector-c-8.0.27-r1.ebuild
@@ -0,0 +1,123 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+CMAKE_ECLASS=cmake
+inherit cmake-multilib flag-o-matic
+
+# wrap the config script
+MULTILIB_CHOST_TOOLS=( /usr/bin/mysql_config )
+
+DESCRIPTION="C client library for MariaDB/MySQL"
+HOMEPAGE="https://dev.mysql.com/downloads/"
+
+if [[ ${PV} == "9999" ]]; then
+	EGIT_REPO_URI="https://github.com/mysql/mysql-server.git"
+
+	inherit git-r3
+else
+	SRC_URI="https://dev.mysql.com/get/Downloads/MySQL-$(ver_cut 1-2)/mysql-boost-${PV}.tar.gz"
+	KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86"
+
+	S="${WORKDIR}/mysql-${PV}"
+fi
+
+LICENSE="GPL-2"
+SLOT="0/21"
+IUSE="ldap static-libs"
+
+RDEPEND="
+	>=app-arch/lz4-0_p131:=[${MULTILIB_USEDEP}]
+	app-arch/zstd:=[${MULTILIB_USEDEP}]
+	sys-libs/zlib:=[${MULTILIB_USEDEP}]
+	ldap? ( dev-libs/cyrus-sasl:=[${MULTILIB_USEDEP}] )
+	dev-libs/openssl:0=[${MULTILIB_USEDEP}]
+"
+DEPEND="${RDEPEND}"
+
+# Avoid file collisions, #692580
+RDEPEND+=" !<dev-db/mysql-5.6.45-r1"
+RDEPEND+=" !=dev-db/mysql-5.7.23*"
+RDEPEND+=" !=dev-db/mysql-5.7.24*"
+RDEPEND+=" !=dev-db/mysql-5.7.25*"
+RDEPEND+=" !=dev-db/mysql-5.7.26-r0"
+RDEPEND+=" !=dev-db/mysql-5.7.27-r0"
+RDEPEND+=" !<dev-db/percona-server-5.7.26.29-r1"
+
+DOCS=( README )
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-8.0.22-always-build-decompress-utilities.patch
+	"${FILESDIR}"/${PN}-8.0.19-do-not-install-comp_err.patch
+	"${FILESDIR}"/${PN}-8.0.27-add-OpenSSL-3.0.0-support.patch
+	"${FILESDIR}"/${PN}-8.0.27-res_n.patch
+)
+
+src_prepare() {
+	sed -i -e 's/CLIENT_LIBS/CONFIG_CLIENT_LIBS/' "scripts/CMakeLists.txt" || die
+
+	# All these are for the server only.
+	# Disable rpm call which would trigger sandbox, #692368
+	sed -i \
+		-e '/MYSQL_CHECK_LIBEVENT/d' \
+		-e '/MYSQL_CHECK_RAPIDJSON/d' \
+		-e '/MYSQL_CHECK_ICU/d' \
+		-e '/MYSQL_CHECK_EDITLINE/d' \
+		-e '/MYSQL_CHECK_CURL/d' \
+		-e '/ADD_SUBDIRECTORY(man)/d' \
+		-e '/ADD_SUBDIRECTORY(share)/d' \
+		-e '/INCLUDE(cmake\/boost/d' \
+		-e 's/MY_RPM rpm/MY_RPM rpmNOTEXISTENT/' \
+		CMakeLists.txt || die
+
+	# Skip building clients
+	echo > client/CMakeLists.txt || die
+
+	# Forcefully disable auth plugin
+	if ! use ldap ; then
+		sed -i -e '/MYSQL_CHECK_SASL/d' CMakeLists.txt || die
+		echo > libmysql/authentication_ldap/CMakeLists.txt || die
+	fi
+
+	cmake_src_prepare
+}
+
+multilib_src_configure() {
+	CMAKE_BUILD_TYPE="RelWithDebInfo"
+
+	# Code is now requiring C++17 due to https://github.com/mysql/mysql-server/commit/236ab55bedd8c9eacd80766d85edde2a8afacd08
+	append-cxxflags -std=c++17
+
+	local mycmakeargs=(
+		-DCMAKE_C_FLAGS_RELWITHDEBINFO=-DNDEBUG
+		-DCMAKE_CXX_FLAGS_RELWITHDEBINFO=-DNDEBUG
+		-DINSTALL_LAYOUT=RPM
+		-DINSTALL_LIBDIR=$(get_libdir)
+		-DWITH_DEFAULT_COMPILER_OPTIONS=OFF
+		-DENABLED_LOCAL_INFILE=ON
+		-DMYSQL_UNIX_ADDR="${EPREFIX}/run/mysqld/mysqld.sock"
+		-DWITH_LZ4=system
+		-DWITH_NUMA=OFF
+		-DWITH_SSL=system
+		-DWITH_ZLIB=system
+		-DWITH_ZSTD=system
+		-DLIBMYSQL_OS_OUTPUT_NAME=mysqlclient
+		-DSHARED_LIB_PATCH_VERSION="0"
+		-DCMAKE_POSITION_INDEPENDENT_CODE=ON
+		-DWITHOUT_SERVER=ON
+	)
+
+	cmake_src_configure
+}
+
+multilib_src_install_all() {
+	doman \
+		man/my_print_defaults.1 \
+		man/perror.1 \
+		man/zlib_decompress.1
+
+	if ! use static-libs ; then
+		find "${ED}" -name "*.a" -delete || die
+	fi
+}