crud: explicitly convert select options that can be tuples to tables

In scope of tarantool/tarantool#8147, box tuples returned from remote
procedure calls our now encoded as a new extension, `MP_TUPLE`, and, as,
the results of such calls are now decoded as box tuples, i.e., cdata. For
compatibility with this feature, we need to explicitly convert tuple fields
of select options, which are returned from a remote procedure calls, to
tables.

Needed for tarantool/tarantool#8147

Author: CuriousGeorgiy

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 * Compatibility with Tarantool 3.0 binary protocol change (#390).
+* Compatibility with Tarantool 3.0 tuple objects (#390).
 
 ## [1.4.0] - 16-10-23
 

crud/select.lua

@@ -30,6 +30,15 @@ function checkers.vshard_call_mode(p)
 end
 
 local function select_on_storage(space_name, index_id, conditions, opts)
+    -- For compatibility with IPROTO_CALL_RET_TUPLE_EXTENSION feature.
+    if opts ~= nil then
+        if box.tuple.is(opts.scan_value) then
+            opts.scan_value = opts.scan_value:totable()
+        end
+        if box.tuple.is(opts.after_tuple) then
+            opts.after_tuple = opts.after_tuple:totable()
+        end
+    end
     dev_checks('string', 'number', '?table', {
         scan_value = 'table',
         after_tuple = '?table',