issue #163 simplify defer statement and fix memory leak

src/lfunc.c

@@ -149,14 +149,15 @@ int luaF_close (lua_State *L, StkId level, int status) {
   UpVal *uv;
   while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
     lua_assert(upisopen(uv));
-    L->openupval = uv->u.open.next;  /* remove from 'open' list */
-    if (uv->refcount == 0) {         /* no references? */
-      if (uv->flags && ttisfunction(uv->v)) {
+    L->openupval = uv->u.open.next; /* remove from 'open' list */
+    if (uv->refcount == 0) {        /* no references? */
+      UpVal uv1 = *uv;              /* copy the upvalue as we will free it below */
+      luaM_free(L, uv);             /* free upvalue before invoking any deferred functions */
+      if (uv1.flags && ttisfunction(uv1.v)) {
         ptrdiff_t levelrel = savestack(L, level);
-        status = calldeferredfunction(L, uv->v, status);
+        status = calldeferredfunction(L, uv1.v, status);
         level = restorestack(L, levelrel);
       }
-      luaM_free(L, uv);              /* free upvalue */ /* FIXME leak if error occurs above */
     }
     else {
       setobj(L, &uv->u.value, uv->v);  /* move value to upvalue slot */

src/lparser.c

@@ -1298,13 +1298,15 @@ static void body (LexState *ls, expdesc *e, int ismethod, int line, int deferred
   new_fs.f = addprototype(ls);
   new_fs.f->linedefined = line;
   open_func(ls, &new_fs, &bl);
-  checknext(ls, '(');
-  if (ismethod) {
-    new_localvarliteral(ls, "self");  /* create 'self' parameter */
-    adjustlocalvars(ls, 1);
+  if (!deferred) {
+    checknext(ls, '(');
+    if (ismethod) {
+      new_localvarliteral(ls, "self");  /* create 'self' parameter */
+      adjustlocalvars(ls, 1);
+    }
+    parlist(ls);
+    checknext(ls, ')');
   }
-  parlist(ls);
-  checknext(ls, ')');
   statlist(ls);
   new_fs.f->lastlinedefined = ls->linenumber;
   check_match(ls, TK_END, TK_FUNCTION, line);
@@ -2359,8 +2361,7 @@ static void statement (LexState *ls) {
       break;
     }
     case TK_DEFER: {  /* stat -> deferstat */
-      luaX_next(ls);  /* skip LOCAL */
-      checknext(ls, TK_FUNCTION);
+      luaX_next(ls);  /* skip DEFER */
       localfunc(ls, 1);
       break;
     }