FFI: Fix pragma push stack limit check and throw on overflow.

Reported by Sergey Kaplun. #1114

1 files changed, 3 insertions, 1 deletions

diff --git a/src/lj_cparse.c b/src/lj_cparse.c
index f807c5ae..2ef7dbe1 100644
--- a/src/lj_cparse.c
+++ b/src/lj_cparse.c
@@ -1747,9 +1747,11 @@ static void cp_pragma(CPState *cp, BCLine pragmaline)
     cp_check(cp, '(');
     if (cp->tok == CTOK_IDENT) {
       if (cp->str->hash == H_(738e923c,a1b65954)) {  /* push */
-        if (cp->curpack < CPARSE_MAX_PACKSTACK) {
+        if (cp->curpack < CPARSE_MAX_PACKSTACK-1) {
           cp->packstack[cp->curpack+1] = cp->packstack[cp->curpack];
           cp->curpack++;
+        } else {
+          cp_errmsg(cp, cp->tok, LJ_ERR_XLEVELS);
         }
       } else if (cp->str->hash == H_(6c71cf27,6c71cf27)) {  /* pop */
         if (cp->curpack > 0) cp->curpack--;