diff --git a/3rd/lua/lapi.c b/3rd/lua/lapi.c
index 348b149f..3d854509 100644
--- a/3rd/lua/lapi.c
+++ b/3rd/lua/lapi.c
@@ -1017,16 +1017,32 @@ static void cloneproto (lua_State *L, Proto *f, const Proto *src) {
   /* copy constants and nested proto */
   int i,n;
   n = src->sp->sizek;
-  f->k=luaM_newvector(L,n,TValue);
-  for (i=0; i<n; i++) setnilvalue(&f->k[i]);
-  for (i=0; i<n; i++) {
-    const TValue *s=&src->k[i];
-    TValue *o=&f->k[i];
-    if (ttisstring(s)) {
-      TString * str = luaS_clonestring(L,tsvalue(s));
-      setsvalue2n(L,o,str);
-    } else {
-      setobj(L,o,s);
+  if (src->sp->sharedk)
+    f->k = src->sp->k;
+  else {
+    lu_byte sharedk = 1;
+    f->k=luaM_newvector(L,n,TValue);
+    for (i=0; i<n; i++) setnilvalue(&f->k[i]);
+    for (i=0; i<n; i++) {
+      const TValue *s=&src->k[i];
+      TValue *o=&f->k[i];
+      if (ttisstring(s)) {
+        TString * sstr = tsvalue(s);
+        if (ttisshrstring(s)) {
+          TString * str = luaS_clonestring(L,sstr);
+          setsvalue2n(L,o,str);
+          if (str != sstr)
+            sharedk = 0;
+        } else {
+          setsvalue2n(L,o,sstr);
+        }
+      } else {
+        setobj(L,o,s);
+      }
+    }
+    if (sharedk) {
+      luaM_freearray(L, f->k, n);
+      f->k = src->sp->k;
     }
   }
   n = src->sp->sizep;
diff --git a/3rd/lua/lauxlib.c b/3rd/lua/lauxlib.c
index e54d3376..63387b7b 100644
--- a/3rd/lua/lauxlib.c
+++ b/3rd/lua/lauxlib.c
@@ -1152,6 +1152,8 @@ static int cache_mode(lua_State *L) {
 	return 0;
 }
 
+LUA_API void luaS_expandshr(int n);
+
 LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
                                              const char *mode) {
   int level = cache_level(L);
@@ -1171,6 +1173,7 @@ LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
     lua_pushliteral(L, "New state failed");
     return LUA_ERRMEM;
   }
+  luaS_expandshr(4096);
   int err = luaL_loadfilex_(eL, filename, mode);
   if (err != LUA_OK) {
     size_t sz = 0;
diff --git a/3rd/lua/lfunc.c b/3rd/lua/lfunc.c
index 1d011aa0..9c0c911f 100644
--- a/3rd/lua/lfunc.c
+++ b/3rd/lua/lfunc.c
@@ -122,26 +122,33 @@ Proto *luaF_newproto (lua_State *L, SharedProto *sp) {
     sp->linedefined = 0;
     sp->lastlinedefined = 0;
     sp->source = NULL;
+    sp->k = NULL;
+    sp->sharedk = 0;
   }
   f->sp = sp;
   return f;
 }
 
 
-static void freesharedproto (lua_State *L, SharedProto *f) {
-  if (f == NULL || G(L) != f->l_G)
+static void freesharedproto (lua_State *L, Proto *pf) {
+  SharedProto *f = pf->sp;
+  if (f == NULL)
     return;
-  luaM_freearray(L, f->code, f->sizecode);
-  luaM_freearray(L, f->lineinfo, f->sizelineinfo);
-  luaM_freearray(L, f->locvars, f->sizelocvars);
-  luaM_freearray(L, f->upvalues, f->sizeupvalues);
-  luaM_free(L, f);
+  if (G(L) == f->l_G) {
+    luaM_freearray(L, f->code, f->sizecode);
+    luaM_freearray(L, f->lineinfo, f->sizelineinfo);
+    luaM_freearray(L, f->locvars, f->sizelocvars);
+    luaM_freearray(L, f->upvalues, f->sizeupvalues);
+    luaM_freearray(L, f->k, f->sizek);
+    luaM_free(L, f);
+  } else if (pf->k != f->k) {
+    luaM_freearray(L, pf->k, f->sizek);
+  }
 }
 
 void luaF_freeproto (lua_State *L, Proto *f) {
   luaM_freearray(L, f->p, f->sp->sizep);
-  luaM_freearray(L, f->k, f->sp->sizek);
-  freesharedproto(L, f->sp);
+  freesharedproto(L, f);
   luaM_free(L, f);
 }
 
diff --git a/3rd/lua/lgc.c b/3rd/lua/lgc.c
index eeb5401e..a5677130 100644
--- a/3rd/lua/lgc.c
+++ b/3rd/lua/lgc.c
@@ -497,7 +497,7 @@ static int traverseproto (global_State *g, Proto *f) {
     f->cache = NULL;  /* allow cache to be collected */
   if (f->sp == NULL)
     return sizeof(Proto);
-  nk = (f->k == NULL) ? 0 : f->sp->sizek;
+  nk = (f->k == f->sp->k && g != f->sp->l_G) ? 0 : f->sp->sizek;
   np = (f->p == NULL) ? 0 : f->sp->sizep;
   for (i = 0; i < nk; i++)  /* mark literals */
     markvalue(g, &f->k[i]);
diff --git a/3rd/lua/lobject.h b/3rd/lua/lobject.h
index 8318005c..b537d392 100644
--- a/3rd/lua/lobject.h
+++ b/3rd/lua/lobject.h
@@ -404,6 +404,7 @@ typedef struct SharedProto {
   lu_byte numparams;  /* number of fixed parameters */
   lu_byte is_vararg;
   lu_byte maxstacksize;  /* number of registers needed by this function */
+  lu_byte sharedk;  /* constants can be shared directly */
   int sizeupvalues;  /* size of 'upvalues' */
   int sizek;  /* size of 'k' */
   int sizecode;
@@ -418,6 +419,7 @@ typedef struct SharedProto {
   LocVar *locvars;  /* information about local variables (debug information) */
   Upvaldesc *upvalues;  /* upvalue information */
   TString  *source;  /* used for debug information */
+  TValue *k;  /* Shared constants */
 } SharedProto;
 
 /*
diff --git a/3rd/lua/lparser.c b/3rd/lua/lparser.c
index 2a5cbf1e..9e0af8bc 100644
--- a/3rd/lua/lparser.c
+++ b/3rd/lua/lparser.c
@@ -550,6 +550,14 @@ static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) {
   enterblock(fs, bl, 0);
 }
 
+static lu_byte check_shortstring(const TValue *k, int sizek) {
+  int i;
+  for (i=0;i<sizek;i++) {
+    if (ttisshrstring(&k[i]))
+      return 0;
+  }
+  return 1;
+}
 
 static void close_func (LexState *ls) {
   lua_State *L = ls->L;
@@ -563,6 +571,8 @@ static void close_func (LexState *ls) {
   luaM_reallocvector(L, sp->lineinfo, sp->sizelineinfo, fs->pc, int);
   sp->sizelineinfo = fs->pc;
   luaM_reallocvector(L, f->k, sp->sizek, fs->nk, TValue);
+  sp->sharedk = check_shortstring(f->k, fs->nk);
+  sp->k = f->k;
   sp->sizek = fs->nk;
   luaM_reallocvector(L, f->p, sp->sizep, fs->np, Proto *);
   sp->sizep = fs->np;
diff --git a/3rd/lua/lstring.c b/3rd/lua/lstring.c
index b7a47fae..3bd7da69 100644
--- a/3rd/lua/lstring.c
+++ b/3rd/lua/lstring.c
@@ -397,7 +397,8 @@ internshrstr (lua_State *L, const char *str, size_t l) {
 
 LUA_API void
 luaS_expandshr(int n) {
-  ATOM_ADD(&SSM.n, n);
+  if (SSM.n < n)
+    ATOM_ADD(&SSM.n, n);
 }
 
 LUAI_FUNC TString *
diff --git a/3rd/lua/lundump.c b/3rd/lua/lundump.c
index bd7dd32d..86057037 100644
--- a/3rd/lua/lundump.c
+++ b/3rd/lua/lundump.c
@@ -119,7 +119,9 @@ static void LoadConstants (LoadState *S, Proto *f) {
   int i;
   int n = LoadInt(S);
   f->k = luaM_newvector(S->L, n, TValue);
+  f->sp->k = f->k;
   f->sp->sizek = n;
+  f->sp->sharedk = 1;
   for (i = 0; i < n; i++)
     setnilvalue(&f->k[i]);
   for (i = 0; i < n; i++) {
@@ -139,6 +141,8 @@ static void LoadConstants (LoadState *S, Proto *f) {
       setivalue(o, LoadInteger(S));
       break;
     case LUA_TSHRSTR:
+      f->sp->sharedk = 0;
+      //fall-through
     case LUA_TLNGSTR:
       setsvalue2n(S->L, o, LoadString(S));
       break;