[Ecls-list] segfault in DAYLIGHT-SAVING-TIME-P

[Goffioul Michael]

> > (decode-universal-time 157768516)
> Segmentation violation.
> Broken at DECODE-UNIVERSAL-TIME.
> 
> This problems happens for some specific given time range. 
> Debugging slightly
> more, it appears that the crash occurs in 
> daylight-saving-time-p because
> the localtime() call returned NULL. MSDN tells me that 
> localtime() returns
> NULL if the time given as argument is before midnight, 
> January 1st, 1970.

Further info: with the above time value, the UTC computed in
daylight-saving-time-p is -1484, which is indeed before 01/01/1970-00:00,
hence localtime() returns NULL.

Michael.