Bug: 'lua_load' does not preserve the stack

'lua_load' does not preserve the stack through the calls to the
reader function, as it should. Immediately after the first call (to
detect whether chunk is binary) it adds stuff, and it also adds a new
table when starting the compilation of each new function.

1 files changed, 5 insertions, 8 deletions

diff --git a/lundump.c b/lundump.c
index 3b61cc8c..d5fdc64b 100644
--- a/lundump.c
+++ b/lundump.c
@@ -392,7 +392,8 @@ static void checkHeader (LoadState *S) {
 /*
 ** Load precompiled chunk.
 */
-LClosure *luaU_undump (lua_State *L, ZIO *Z, const char *name, int fixed) {
+LClosure *luaU_undump (lua_State *L, ZIO *Z, Table *anchor, const char *name,
+                       int fixed) {
   LoadState S;
   LClosure *cl;
   if (*name == '@' || *name == '=')
@@ -405,20 +406,16 @@ LClosure *luaU_undump (lua_State *L, ZIO *Z, const char *name, int fixed) {
   S.fixed = cast_byte(fixed);
   S.offset = 1;  /* fist byte was already read */
   checkHeader(&S);
-  cl = luaF_newLclosure(L, loadByte(&S));
-  setclLvalue2s(L, L->top.p, cl);
-  luaD_inctop(L);
-  S.h = luaH_new(L);  /* create list of saved strings */
+  S.h = anchor;
   S.nstr = 0;
-  sethvalue2s(L, L->top.p, S.h);  /* anchor it */
-  luaD_inctop(L);
+  cl = luaF_newLclosure(L, loadByte(&S));
+  luaD_anchorobj(L, anchor, obj2gco(cl));
   cl->p = luaF_newproto(L);
   luaC_objbarrier(L, cl, cl->p);
   loadFunction(&S, cl->p);
   if (cl->nupvalues != cl->p->sizeupvalues)
     error(&S, "corrupted chunk");
   luai_verifycode(L, cl->p);
-  L->top.p--;  /* pop table */
   return cl;
 }