php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Bug #75664 sprintf %u results in 0 for numbers with more digits than PHP_INT_MAX
Submitted: 2017-12-10 23:35 UTC Modified: 2017-12-11 22:25 UTC
From: erik at evanv dot nl Assigned: cmb (profile)
Status: Not a bug Package: Strings related
PHP Version: 7.2.0 OS: linux 4.14.4
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: erik at evanv dot nl
New email:
PHP Version: OS:

 

 [2017-12-10 23:35 UTC] erik at evanv dot nl 
Description:
------------
Code speaks for itself. This can lead to data corruption.

A decent solution would be to display unknown least significant digits as 0 just like %f.

Alternative would be an ArithmeticError.

Test script:
---------------
php > $var = PHP_INT_MAX * 2;
php > echo sprintf("%f", $var);
18446744073709551616.000000
php > echo sprintf("%u", $var);
0

Expected result:
----------------
18446744073709551616

Actual result:
--------------
0

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2017-12-11 15:25 UTC] cmb@php.net
-Status: Open +Status: Not a bug -Assigned To: +Assigned To: cmb
 [2017-12-11 15:25 UTC] cmb@php.net 
Actually, this boils down to `(int) (PHP_INT_MAX*2)` being
undefined[1], so this is not a bug.

[1] <http://www.php.net/manual/en/language.types.integer.php#language.types.integer.casting.from-float>
 [2017-12-11 19:47 UTC] erik at evanv dot nl 
I hope you can consider adding an error for this. Silently overflowing to zero is not something you expect to be possible in a managed language. 

This behavior caused data corruption in my company's product. I was certain it was caused by a C program we were using but to my surprise it was this.
 [2017-12-11 22:25 UTC] cmb@php.net 
I have to admit that the present behavior is not optimal.
However, changing it would require the RFC process.  Feel free to
start it; see <https://wiki.php.net/rfc/howto>.
 
PHP Copyright © 2001-2024 The PHP Group
All rights reserved. 		Last updated: Sat Dec 21 13:01:31 2024 UTC