luci-base: utils: support multiple return values in util.ubus()

This is needed to deal with ubus methods that return multiple results,
e.g. session/list

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
(cherry picked from commit 9ead1e29a6404c5ba3a438a3f8a68b6a3dcaee3f)

diff --git a/modules/luci-base/luasrc/util.lua b/modules/luci-base/luasrc/util.lua
index 10428b0b35f707d26b42ca492fa94bf94713991b..f16b3afb2e236ef3489cb58b14ab9e1cf893c2d7 100644 (file)
--- a/modules/luci-base/luasrc/util.lua
+++ b/modules/luci-base/luasrc/util.lua
@@ -16,7 +16,7 @@ local _ubus = require "ubus"
 local _ubus_connection = nil
 
 local getmetatable, setmetatable = getmetatable, setmetatable
-local rawget, rawset, unpack = rawget, rawset, unpack
+local rawget, rawset, unpack, select = rawget, rawset, unpack, select
 local tostring, type, assert, error = tostring, type, assert, error
 local ipairs, pairs, next, loadstring = ipairs, pairs, next, loadstring
 local require, pcall, xpcall = require, pcall, xpcall
@@ -647,6 +647,17 @@ local ubus_codes = {
        "CONNECTION_FAILED"
 }
 
+local function ubus_return(...)
+       if select('#', ...) == 2 then
+               local rv, err = select(1, ...), select(2, ...)
+               if rv == nil and type(err) == "number" then
+                       return nil, err, ubus_codes[err]
+               end
+       end
+
+       return ...
+end
+
 function ubus(object, method, data)
        if not _ubus_connection then
                _ubus_connection = _ubus.connect()
@@ -657,8 +668,7 @@ function ubus(object, method, data)
                if type(data) ~= "table" then
                        data = { }
                end
-               local rv, err = _ubus_connection:call(object, method, data)
-               return rv, err, ubus_codes[err]
+               return ubus_return(_ubus_connection:call(object, method, data))
        elseif object then
                return _ubus_connection:signatures(object)
        else