FFI: Fix cdata equality comparison against strings.

2 files changed, 5 insertions, 3 deletions

diff --git a/src/lj_carith.c b/src/lj_carith.c
index 92fe5597..36d7abb1 100644
--- a/src/lj_carith.c
+++ b/src/lj_carith.c
@@ -62,7 +62,7 @@ static int carith_checkarg(lua_State *L, CTState *cts, CDArith *ca)
       TValue *o2 = i == 0 ? o+1 : o-1;
       CType *ct = ctype_raw(cts, cdataV(o2)->ctypeid);
       ca->ct[i] = NULL;
-      ca->p[i] = NULL;
+      ca->p[i] = (uint8_t *)strVdata(o);
       ok = 0;
       if (ctype_isenum(ct->info)) {
         CTSize ofs;
@@ -73,7 +73,7 @@ static int carith_checkarg(lua_State *L, CTState *cts, CDArith *ca)
           ok = 1;
         } else {
           ca->ct[1-i] = ct;  /* Use enum to improve error message. */
-          ca->p[1-i] = (void *)(intptr_t)1;  /* To make it unequal. */
+          ca->p[1-i] = NULL;
           break;
         }
       }
diff --git a/src/lj_crecord.c b/src/lj_crecord.c
index 71f3d069..8612f005 100644
--- a/src/lj_crecord.c
+++ b/src/lj_crecord.c
@@ -1421,7 +1421,9 @@ void LJ_FASTCALL recff_cdata_arith(jit_State *J, RecordFFData *rd)
           ct = ctype_child(cts, cct);
           tr = lj_ir_kint(J, (int32_t)ofs);
         }  /* else: interpreter will throw. */
-      }  /* else: interpreter will throw. */
+      } else {
+        tr = emitir(IRT(IR_ADD, IRT_PTR), tr, lj_ir_kintp(J, sizeof(GCstr)));
+      }
     } else if (!tref_isnum(tr)) {
       tr = 0;
     }