[Tarantool-patches] [PATCH luajit] Restore state when recording __concat metamethod throws an error.

[Sergey Kaplun]

Hi, Sergey!
Thanks for the review!

On 13.09.24, Sergey Bronnikov wrote:
> Hi, Sergey,
> 
> thanks for the patch! LGTM with a minor comment. See below.
> 
> On 21.08.2024 11:23, Sergey Kaplun wrote:
> 
> 
> <snipped>
> 
> > +-- Need to use metamethod call in the concat recording.
> > +debug.setmetatable(nil, {
> I propose to add a comment that explain why `nil` is used here.

I've removed the nil usage to avoid confusion.
Branch is rebased on the current master and force-pushed.
===================================================================
diff --git a/test/tarantool-tests/lj-1234-err-in-record-concat.test.lua b/test/tarantool-tests/lj-1234-err-in-record-concat.test.lua
index 9abaeba5..4fe02708 100644
--- a/test/tarantool-tests/lj-1234-err-in-record-concat.test.lua
+++ b/test/tarantool-tests/lj-1234-err-in-record-concat.test.lua
@@ -12,12 +12,13 @@ test:plan(2)
 
 jit.opt.start('hotloop=1')
 
-local __concat = function(v1, v2)
-    return tostring(v1) .. tostring(v2)
+local __concat = function()
+  return ''
 end
 
 -- Need to use metamethod call in the concat recording.
-debug.setmetatable(nil, {
+-- Let's use a table with the metamethod.
+local concatable_t = setmetatable({}, {
   __concat = __concat,
 })
 
@@ -31,7 +32,7 @@ local function test_concat_p()
     -- `lj_record_ret()` restore the Lua stack (before the patch),
     -- it becomes unbalanced after the instruction recording
     -- attempt.
-    local _ = {} .. (nil .. nil)
+    local _ = {} .. (concatable_t .. concatable_t)
   end
 end
 
===================================================================

> > +  __concat = __concat,
> > +})
> > +

<snipped>

-- 
Best regards,
Sergey Kaplun