Edit report at https://bugs.php.net/bug.php?id=53608&edit=1
ID: 53608
Updated by: derick@php.net
Reported by: jer_826 at yahoo dot com
Summary: mktime() produces invalid results under 64-bit
-Status: Verified
+Status: Wont fix
Type: Bug
Package: Date/time related
Operating System: Linux 2.6.35.7 x86_64
PHP Version: 5.2.16
Block user comment: N
Private report: N
New Comment:
Adding overflow detection here would make things really cumbersome and slower, and IMO it's not
worth the effort.
Previous Comments:
------------------------------------------------------------------------
[2011-03-31 12:05:49] cataphract@php.net
I think the only reasonable fix here is to check the range of the arguments on the beginning of the
function. Checking for overflow everywhere doesn't seem very handy since there are lots of
places and functions (which would have to be changed to signal overflow errors) where this would
have to be done.
------------------------------------------------------------------------
[2011-01-04 07:39:58] aharvey@php.net
Confirmed; the error handling in timelib_date_to_int() is insufficient
for platforms with 64 bit longs.
The quick and dirty fix would be to explicitly compare ts in
timelib_date_to_int() to the minimum and maximum values of a 32 bit
integer, but you'd then lose the ability to use mktime() for dates
outside the 1901-2038 range. Better would be to try to detect overflow
in timelib_update_ts(), but that's not going to be foolproof either.
I don't have any particularly strong feelings on this one, or even
whether it's worth trying to handle. Derick?
------------------------------------------------------------------------
[2011-01-02 09:52:16] brad at njoe dot com
Confirmed on Ubuntu 10.10 (Linux 2.6.35-24-server x86_64). Also tested a Win32
build and all three var_dumps() show "bool(false)" as expected/documented.
------------------------------------------------------------------------
[2010-12-24 22:19:04] jer_826 at yahoo dot com
Description:
------------
It appears that when the PHP binary was compiled against 64-bit libraries,
mktime() seems to only do minimal error checking of parms. After some additional
testing, if found the following results:
PHP Code:
$t=mktime(0,0,0,12,3,292277026596);
var_dump($t);
$t=mktime(0,0,0,12,3,292277026597);
var_dump($t);
$t=mktime(900000000000,900000000000,900000000000,900000000000,900000000000,90000
0000000);
var_dump($t);
int(9223372036854655200)
int(-9223372036823360416)
int(-6044405109589065632)
It appears that once the parm value exceeds the value limit of a long var, the
function returns a negative value. No warnings are produced. Instead of
returning FALSE for an error, the function just returns an invalid result.
Some additional info here: http://phpbuilder.com/board/showthread.php?
p=10971046#post10971046
Test script:
---------------
$t=mktime(0,0,0,12,3,292277026596);
var_dump($t);
$t=mktime(0,0,0,12,3,292277026597);
var_dump($t);
$t=mktime(900000000000,900000000000,900000000000,900000000000,900000000000,900000000000);
var_dump($t);
int(9223372036854655200)
int(-9223372036823360416)
int(-6044405109589065632)
Expected result:
----------------
Return FALSE if parms are invalid.
Actual result:
--------------
Invalid values. Does not return FALSE.
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=53608&edit=1