Edit report at https://bugs.php.net/bug.php?id=49510&edit=1
ID: 49510
Comment by: pgarvin76 at gmail dot com
Reported by: m dot kurzyna at crystalpoint dot pl
Summary: boolean validation fails with FILTER_NULL_ON_FAILURE
Status: Assigned
Type: Feature/Change Request
Package: Filter related
Operating System: Linux
PHP Version: 5.3.0
Assigned To: pajoye
Block user comment: N
Private report: N
New Comment:
There was a fix committed in branch 5.4.8
(a26390ef0c22be3637795d9b5ab1c445e1d3f847). But the problem still persists for
me. The test file (bug49510.phpt) fails on my fresh build.
Previous Comments:
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[2012-09-12 20:22:38] dernelson at corelogic dot com
The question the developer is asking filter_var() is: "is boolean FALSE a valid
boolean", and the answer filter_var() is giving back is "nope." Regardless of
the technical details underlying the implementation, there is an obvious
problem here.
Short of changing PHP so that (string)FALSE === '0' (hah), I would suggest an
explicit test case for boolean FALSE values, so that the function can return
boolean FALSE in those cases, instead of NULL.
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[2012-07-15 04:57:34] s...@php.net
Filters operate on strings. So any value that is passed to the filter_var()
will
be coerced into string. This means (boolean)false and '' is exactly the same
for
the filter. And that means the callbacks will be receiving strings too.
Now, the docs specifically say '' is a valid value for "boolean" filter and is
converted to false, so '' should not return NULL with FILTER_NULL_ON_FAILURE I
guess since it's documented not to be failure value.
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[2012-06-24 00:34:38] 2072 at teaser dot fr
Knowing this issue I wanted to make a boolean validation filter of my own using
FILTER_CALLBACK but it suffers from the same problem, these filters are not
"boolean safe".
It appears that what is to be validated is first converted to a string.
So when given (bool)true my callback actually receives (string)'1' and
(string)'' when given (bool)false.
There is definitely something wrong.
(I'm using PHP 5.3.8)
------------------------------------------------------------------------
[2010-09-01 13:55:06] schkovich at gmail dot com
filter_var(false,FILTER_VALIDATE_BOOLEAN,FILTER_NULL_ON_FAILURE)
// got NULL, expected false
That does not make sense at all! Further on, I have to agree with m.kurzyna
that since false === (bool)""
filter_var("",FILTER_VALIDATE_BOOLEAN,FILTER_NULL_ON_FAILURE) should
return FALSE and not NULL.
Basically, as implemented, getting FALSE from
filter_var(false,FILTER_VALIDATE_BOOLEAN) means that validation failed. It
appears to be a design problem since filter_var() as
specified will return FALSE if the filter fails making it impossible to
distinguish if filter failed or valid FALSE value is returned. Therefore,
instead returning FALSE if
filter fails perhaps warning could be issued or even better exception thrown.
On addition when voting I've wrongly selected that I am not using the same
version and the same operating system. Correct ones are:
PHP Version => 5.3.2-1ubuntu4.2
System => Linux schkovich 2.6.32-24-generic #42-Ubuntu SMP Fri Aug 20 14:21:58
UTC 2010 x86_64
------------------------------------------------------------------------
[2009-09-10 11:24:37] m dot kurzyna at crystalpoint dot pl
As much as i'd like to have empty string be invalid false cast i have to
disagree with you for consistency reasons.
If (boolean)'' == false then filter_var('','boolean') should also return false.
Both in general and in case of FILTER_NULL_ON_FAILURE (just like the
documentation states).
Also, because i can't stress it enough, this is a VALIDATOR not a SANITIZER so
using it as a strict caster is secondary to it's validation purpose and as such
it currently fails both on implied and explicit behavior.
The ideal solution would be to have FILTER_VALIDATE_BOOLEAN roughly equal to
current behavior with FILTER_NULL_ON_FAILURE and a *seperate*
FILTER_SANITIZE_BOOLEAN similar to current behavior w/o the null failure flag.
This however probably is impossible due to BC.
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the rest of the comments, please view the bug report online at
https://bugs.php.net/bug.php?id=49510
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