Added macro 'luaL_pushfail'

The macro 'luaL_pushfail' documents all places in the standard libraries
that return nil to signal some kind of failure. It is defined as
'lua_pushnil'. The manual also got a notation (@fail) to document those
returns. The tests were changed to be agnostic regarding whether 'fail'
is 'nil' or 'false'.

1 files changed, 4 insertions, 0 deletions

diff --git a/lauxlib.h b/lauxlib.h
index f68f6af1..c50cdf4d 100644
--- a/lauxlib.h
+++ b/lauxlib.h
@@ -153,6 +153,10 @@ LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname,
 #define luaL_loadbuffer(L,s,sz,n)       luaL_loadbufferx(L,s,sz,n,NULL)
 
 
+/* push the value used to represent failure/error */
+#define luaL_pushfail(L)        lua_pushnil(L)
+
+
 /*
 ** {======================================================
 ** Generic Buffer manipulation