Re: Missing error message in panic handler / calling luaD_throw without error message on stack

[Jan Behrens <jbe-lua-l@...>]

On Mon, 10 Nov 2014 11:18:57 -0200
Roberto Ierusalimschy <roberto@inf.puc-rio.br> wrote:

> > > Looking into the source code of Lua 5.2.3, I found that in line
> > > #93 of lmem.c, the function luaD_throw(L, LUA_ERRMEM) is called
> > > #without
> > > pushing first an error message on top of the stack. Other calls of
> > > luaD_throw, however, push an error message to the stack, e.g.
> > > function lexerror() in llex.c, line #110 or function checkmode()
> > > in ldo.c, line #635.
> > > 
> > > Is this a bug?
> > 
> > There seems to be a bug, but not there. As lhf pointed out, memory
> > errors are handled differently; the error message for them is
> > pushed in ldo.c, function 'seterrorobj'.
> 
> The bug is that 'seterrorobj' is not called in the case of a panic.
> (For protected calls, the error message "not enough memory" is
> returned correctly.)
> 
> -- Roberto
> 

Thank you for this information. I might just push an error string on
top of the stack as a workaround before calling lua_newuserdata() until
this bug has been fixed.

Regards
Jan Behrens

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