Added an optional parameter to 'coroutine.isyieldable'

1 files changed, 2 insertions, 1 deletions

diff --git a/lcorolib.c b/lcorolib.c
index cdb5fedc..f7c9e165 100644
--- a/lcorolib.c
+++ b/lcorolib.c
@@ -146,7 +146,8 @@ static int luaB_costatus (lua_State *L) {
 
 
 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;
 }