Edit report at https://bugs.php.net/bug.php?id=50688&edit=1
ID: 50688
Comment by: m at rtin dot so
Reported by: jcampbell at remindermedia dot com
Summary: Using exceptions inside usort() callback function
causes a warning
Status: Assigned
Type: Bug
Package: Arrays related
Operating System: Fedora Core 12
PHP Version: 5.*, 6
Assigned To: stas
Block user comment: N
Private report: N
New Comment:
I ran into a similar issue, i'm sure it'll require the same patch as it's the
backtrace causing the problem but worth noting it doesn't require an exception
to
trigger this, just a backtrace.
$ cat usort.php
<?php
set_error_handler(function($errno, $errstr) {
$bt = debug_backtrace();
var_dump($errstr);
});
$arr = [1, 2];
usort($arr, function($a, $b) use ($arr) {
trigger_error('test');
return $a > $b;
});
$ php usort.php
string(4) "test"
string(59) "usort(): Array was modified by the user comparison function"
Previous Comments:
------------------------------------------------------------------------
[2013-07-09 07:21:19] jakub dot lopuszanski at nasza-klasa dot pl
I'd like to add, that you do not have to throw an exception to get this warning.
Mere creating it, also triggers the warning, as in:
<?php
function comp($a,$b){
@new Exception("dupa");
}
$a =array(1,2,3);
usort($a, 'comp');
var_dump($a);
?>
PHP Warning: usort(): Array was modified by the user comparison function in
/home/jlopuszanski/test.php on line 6
------------------------------------------------------------------------
[2013-06-17 11:11:07] andrejs dot verza at gmail dot com
Php 5.4.16 also fails with this.
Still the same status for 3 and a half years old bug?!
------------------------------------------------------------------------
[2012-08-08 17:53:58] mbrowne83 at gmail dot com
This will probably be obvious to most, but I just wanted to mention that you
can always prefix the usort function with the @ symbol to prevent the
warning...of course that would also suppress any other types of notices or
warnings that might occcur anywhere within the sorting function...
------------------------------------------------------------------------
[2012-02-24 18:04:02] keith at breadvault dot com
This same problem arises when using Mockery to mock the object whose method is
being used by usort(), even though the method itself neither is mocked nor
handles
any exceptions. The proxy generated by Mockery must wrap the target class's
methods with some exception-handling code.
Unfortunately this forced me to code a workaround that would not use usort. My
hack extracts from the objects in the array the values being sorted on, sorts
that
array of values using asort() (to preserve the keys), and finally rebuilds the
list of objects using the keys in the order that they appear in the asorted
list
of values. Yuck.
------------------------------------------------------------------------
[2012-02-21 22:56:31] eric_haney at yahoo dot com
It took me a while to figure out that some code called from usort was throwing,
catching, and (gracefully) handling an Exception. Then I found this post.
Quite frustrating.
I turned off warnings with ini_set before calling usort, then turned them on
again after. This is an effective workaround for now, but I'd love to clean
that nastiness out of my code.
It is also my opinion that usort should be allowed to change the elements in
the array. EG: an instance variable of an object may be lazy-loaded as a
result of a method call from within a usort callback. Should a warning really
be issued in that case?
------------------------------------------------------------------------
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https://bugs.php.net/bug.php?id=50688
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