Support for multireturn in wrapped pcall()

src/lua/init.lua

@@ -9,10 +9,13 @@ tarantool_error_message(void);
 ]]
 
 local pcall_lua = pcall
-pcall = function(fun, ...)
-    local status, msg = pcall_lua(fun, ...)
-    if status == false and msg == 'C++ exception' then
+
+local function pcall_wrap(status, ...)
+    if status == false and ... == 'C++ exception' then
         return false, ffi.string(ffi.C.tarantool_error_message())
     end
-    return status, msg
+    return status, ...
+end
+pcall = function(fun, ...)
+    return pcall_wrap(pcall_lua(fun, ...))
 end

test/app/pcall.result

@@ -5,3 +5,5 @@
 pcall inside xpcall:	true	pcall is ok
 pcall with Lua error():	false	some message
 pcall with box.raise():	false	some message
+pcall with no return:	1
+pcall with multireturn:	true	1	2	3

test/app/pcall.test.lua

@@ -28,3 +28,6 @@ local status, msg = pcall(function()
     box.raise(box.error.ER_ILLEGAL_PARAMS, 'some message')
 end)
 print('pcall with box.raise():', status, msg)
+
+print('pcall with no return:', select('#', pcall(function() end)))
+print('pcall with multireturn:', pcall(function() return 1, 2, 3 end))