[Tarantool-patches] [PATCH luajit] Clear stack after print_jit_status() in CLI.

[Sergey Kaplun]

From: Mike Pall <mike>

Suggested by Hydroque.

(cherry picked from commit 03cd5aa749c1bc3bb4b7d4289236b6096cb3dc85)

This patch makes the Lua stack balanced after using the aforementioned
function, which is considered a good practice [1]. Be aware that the
only argument on the stack is dummy NULL from the `lua_cpcall()`, so it
can be easily cleared. This doesn't change the behaviour since all calls
of `print_jit_status()` are followed by `dotty()` with a call to
`loadline()`, which clears the stack anyway.

Sergey Kaplun:
* added the description for the patch

[1]: https://www.lua.org/manual/5.1/manual.html#lua_call

Part of tarantool/tarantool#10199
---

Branch: https://github.com/tarantool/luajit/tree/skaplun/lj-382-clear-stack-after-jit-status
Issue: https://github.com/tarantool/tarantool/issues/10199

 src/luajit.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/luajit.c b/src/luajit.c
index b63c92d1..e04a5a30 100644
--- a/src/luajit.c
+++ b/src/luajit.c
@@ -162,6 +162,7 @@ static void print_jit_status(lua_State *L)
     fputs(s, stdout);
   }
   putc('\n', stdout);
+  lua_settop(L, 0);  /* clear stack */
 }
 
 static void createargtable(lua_State *L, char **argv, int argc, int argf)
-- 
2.46.0