FFI: Fix dangling reference to CType in carith_checkarg().

Reported by Sergey Kaplun. #1108

diff --git a/src/lj_carith.c b/src/lj_carith.c
index 96384e871368541bb1e2cbc8891e190e61ea0a8b..bad5fe66b0d01e6431c7e6b9bfc405b63828f06a 100644 (file)
--- a/src/lj_carith.c
+++ b/src/lj_carith.c
@@ -42,9 +42,13 @@ static int carith_checkarg(lua_State *L, CTState *cts, CDArith *ca)
        p = (uint8_t *)cdata_getptr(p, ct->size);
        if (ctype_isref(ct->info)) ct = ctype_rawchild(cts, ct);
       } else if (ctype_isfunc(ct->info)) {
+       CTypeID id0 = i ? ctype_typeid(cts, ca->ct[0]) : 0;
        p = (uint8_t *)*(void **)p;
        ct = ctype_get(cts,
          lj_ctype_intern(cts, CTINFO(CT_PTR, CTALIGN_PTR|id), CTSIZE_PTR));
+       if (i) {  /* cts->tab may have been reallocated. */
+         ca->ct[0] = ctype_get(cts, id0);
+       }
       }
       if (ctype_isenum(ct->info)) ct = ctype_child(cts, ct);
       ca->ct[i] = ct;