Re: Type-error in C code

["Jan Djärv" <jan.h.d@swipnet.se>]

An Atom is 32 bits.  make_number can't cover that range when long is 32 bits, 
so it is an unsafe thing to do.  Best is to revert and go back to using a string.

	Jan D.


Julien Danjou skrev 2010-11-12 15.21:
> On Fri, Nov 12 2010, Stefan Monnier wrote:
>
>> static void
>> set_wm_state (Lisp_Object frame, int add, Atom atom, Atom value)
>> {
>>    struct x_display_info *dpyinfo = FRAME_X_DISPLAY_INFO (XFRAME (frame));
>>
>>    x_send_client_event (frame, make_number (0), frame,
>>                         dpyinfo->Xatom_net_wm_state,
>>                         make_number (32),
>>                         /* 1 = add, 0 = remove */
>>                         Fcons
>>                         (make_number (add ? 1 : 0),
>>                          Fcons
>>                          (atom,
>>                           value != 0 ? value : Qnil)));
>> }
>>
>> The error is to put an "Atom" into a cons cell: those can only hold
>> Lisp_Objects.  The usual compilation flags won't catch the error because
>> both types are actually some kind of integer, but if you
>> compile --enable-use-lisp-union-type, the C compiler will
>> dutyfully burp.
>
> Good catch Stefan. I should use this flag to compile my code now.
>
> The fix should be easy I think, you just need to replace atom with
> make_number (atom).
>
> I can provide a patch is that handier.
>