libprotobuf-c: Add SOVERSION guard

%ci:no-build

packages/libprotobuf-c/build.sh

@@ -11,6 +11,22 @@ TERMUX_PKG_DEPENDS="libc++, libprotobuf, protobuf"
 TERMUX_PKG_BREAKS="libprotobuf-c-dev"
 TERMUX_PKG_REPLACES="libprotobuf-c-dev"
 
+termux_step_post_get_source() {
+	# Do not forget to bump revision of reverse dependencies and rebuild them
+	# after SOVERSION is changed.
+	local _SOVERSION=1
+
+	local a
+	for a in CURRENT AGE; do
+		local _LT_${a}=$(sed -En 's/^LIBPROTOBUF_C_'"${a}"'=([0-9]+).*/\1/p' \
+				Makefile.am)
+	done
+	local v=$(( _LT_CURRENT - _LT_AGE ))
+	if [ "${v}" != "${_SOVERSION}" ]; then
+		termux_error_exit "SOVERSION guard check failed."
+	fi
+}
+
 termux_step_pre_configure() {
 	termux_setup_protobuf
 	export PROTOC=$(command -v protoc)