From: Fritz Test <[EMAIL PROTECTED]>
Date: 09 Feb 2003 11:25:37 +0100
[...]
With help of the analysis of Jeremy (Thanks) I patched the function
mkgmtime, such that it works for me now. The problem is, that gmtime(&t)
returns a null pointer for my 64-bit system if t is out of some range. I
don't know exactly what range, but I assume that the generated value for
the year must fit in 32 bits?.
Your patch wouldn't work on a system with an unsigned 64-bit time_t.
(The median value would start out very large, and the binary search
would never subtract enough to get down into "normal" time.)
It seems to me that moving
if (bits > 40) { bits = 40; }
to above the
t = (t < 0) ? 0 : ((time_t) 1 << bits);
would fix the problem.
Is my analysis correct?
Larry
Here's a snipped of my code in mkgmtime.c
-----------------------------------------------
/*
** If time_t is signed, then 0 is the median value,
** if time_t is unsigned, then 1 << bits is median.
*/
t = (t < 0) ? 0 : ((time_t) 1 << bits)
;
/* Patch begin */
/*
** On my 32-bit Debian GNU/Linux 3.0 AMD K6 PC, the algorithm
** converges in a range
** from
** 1901-12-13 20:46:00 GMT -> -2147483640
** to
** 2038-01-19 03:14:07 GMT -> 2147483647
*/
/*
** It segfaults on RedHat 7.2/Alpha if bits > 56, since gmtime (&t)
** returns null pointer.
** Hence, set bits to a resonable value <= 56.
**
** Setting, e.g. bits=40, the algorithm converges in a range
** from
** -32873-11-12 23:24:00 GMT -> -1099511627760
** to
** 36812-02-20 00:36:59 GMT -> 1099511627819
*/
if (bits > 40) {
bits = 40;
}
/* patch end */
for ( ; ; ) {
prt (t);
fprintf (stderr, " ");
