1 files changed, 61 insertions, 23 deletions

diff --git a/libs/liblua/src/lcorolib.c b/libs/liblua/src/lcorolib.c
index 0b17af9e34..7d6e585b1d 100644
--- a/libs/liblua/src/lcorolib.c
+++ b/libs/liblua/src/lcorolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lcorolib.c,v 1.10.1.1 2017/04/19 17:20:42 roberto Exp $
+** $Id: lcorolib.c $
 ** Coroutine Library
 ** See Copyright Notice in lua.h
 */
@@ -20,25 +20,24 @@
 
 static lua_State *getco (lua_State *L) {
   lua_State *co = lua_tothread(L, 1);
-  luaL_argcheck(L, co, 1, "thread expected");
+  luaL_argexpected(L, co, 1, "thread");
   return co;
 }
 
 
+/*
+** Resumes a coroutine. Returns the number of results for non-error
+** cases or -1 for errors.
+*/
 static int auxresume (lua_State *L, lua_State *co, int narg) {
-  int status;
+  int status, nres;
   if (!lua_checkstack(co, narg)) {
     lua_pushliteral(L, "too many arguments to resume");
     return -1;  /* error flag */
   }
-  if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
-    lua_pushliteral(L, "cannot resume dead coroutine");
-    return -1;  /* error flag */
-  }
   lua_xmove(L, co, narg);
-  status = lua_resume(co, L, narg);
+  status = lua_resume(co, L, narg, &nres);
   if (status == LUA_OK || status == LUA_YIELD) {
-    int nres = lua_gettop(co);
     if (!lua_checkstack(L, nres + 1)) {
       lua_pop(co, nres);  /* remove results anyway */
       lua_pushliteral(L, "too many results to resume");
@@ -75,8 +74,11 @@ static int luaB_auxwrap (lua_State *L) {
   lua_State *co = lua_tothread(L, lua_upvalueindex(1));
   int r = auxresume(L, co, lua_gettop(L));
   if (r < 0) {
+    int stat = lua_status(co);
+    if (stat != LUA_OK && stat != LUA_YIELD)
+      lua_resetthread(co);  /* close variables in case of errors */
     if (lua_type(L, -1) == LUA_TSTRING) {  /* error object is a string? */
-      luaL_where(L, 1);  /* add extra info */
+      luaL_where(L, 1);  /* add extra info, if available */
       lua_insert(L, -2);
       lua_concat(L, 2);
     }
@@ -108,35 +110,48 @@ static int luaB_yield (lua_State *L) {
 }
 
 
-static int luaB_costatus (lua_State *L) {
-  lua_State *co = getco(L);
-  if (L == co) lua_pushliteral(L, "running");
+#define COS_RUN		0
+#define COS_DEAD	1
+#define COS_YIELD	2
+#define COS_NORM	3
+
+
+static const char *const statname[] =
+  {"running", "dead", "suspended", "normal"};
+
+
+static int auxstatus (lua_State *L, lua_State *co) {
+  if (L == co) return COS_RUN;
   else {
     switch (lua_status(co)) {
       case LUA_YIELD:
-        lua_pushliteral(L, "suspended");
-        break;
+        return COS_YIELD;
       case LUA_OK: {
         lua_Debug ar;
-        if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
-          lua_pushliteral(L, "normal");  /* it is running */
+        if (lua_getstack(co, 0, &ar))  /* does it have frames? */
+          return COS_NORM;  /* it is running */
         else if (lua_gettop(co) == 0)
-            lua_pushliteral(L, "dead");
+            return COS_DEAD;
         else
-          lua_pushliteral(L, "suspended");  /* initial state */
-        break;
+          return COS_YIELD;  /* initial state */
       }
       default:  /* some error occurred */
-        lua_pushliteral(L, "dead");
-        break;
+        return COS_DEAD;
     }
   }
+}
+
+
+static int luaB_costatus (lua_State *L) {
+  lua_State *co = getco(L);
+  lua_pushstring(L, statname[auxstatus(L, co)]);
   return 1;
 }
 
 
 static int luaB_yieldable (lua_State *L) {
-  lua_pushboolean(L, lua_isyieldable(L));
+  lua_State *co = lua_isnone(L, 1) ? L : getco(L);
+  lua_pushboolean(L, lua_isyieldable(co));
   return 1;
 }
 
@@ -148,6 +163,28 @@ static int luaB_corunning (lua_State *L) {
 }
 
 
+static int luaB_close (lua_State *L) {
+  lua_State *co = getco(L);
+  int status = auxstatus(L, co);
+  switch (status) {
+    case COS_DEAD: case COS_YIELD: {
+      status = lua_resetthread(co);
+      if (status == LUA_OK) {
+        lua_pushboolean(L, 1);
+        return 1;
+      }
+      else {
+        lua_pushboolean(L, 0);
+        lua_xmove(co, L, 1);  /* copy error message */
+        return 2;
+      }
+    }
+    default:  /* normal or running coroutine */
+      return luaL_error(L, "cannot close a %s coroutine", statname[status]);
+  }
+}
+
+
 static const luaL_Reg co_funcs[] = {
   {"create", luaB_cocreate},
   {"resume", luaB_coresume},
@@ -156,6 +193,7 @@ static const luaL_Reg co_funcs[] = {
   {"wrap", luaB_cowrap},
   {"yield", luaB_yield},
   {"isyieldable", luaB_yieldable},
+  {"close", luaB_close},
   {NULL, NULL}
 };