Bug #66682 [Nab]: FILTER_VALIDATE_INT fails on strings starting with zero.

Edit report at https://bugs.php.net/bug.php?id=66682&edit=1 ID: 66682 Updated by: yohgaki@php.net Reported by: alex dot howansky at gmail dot com Summary: FILTER_VALIDATE_INT fails on strings starting with zero. Status: Not a bug Type: Bug Package: Filter related Operating System: Linux 2.6 64 PHP Version: 5.5.9 Block user comment: N Private report: N New Comment: Hi Derick, I'm not sure if this behavior is documented somewhere, but it seems strange. Tests do not cover "01.23" nor "01" also, for example. I found this note http://jp2.php.net/manual/en/filter.filters.validate.php but nothing else. Note: As of PHP 5.4.11, the numbers +0 and -0 validate as both integers as well as floats (using FILTER_VALIDATE_FLOAT and FILTER_VALIDATE_INT). Before PHP 5.4.11 they only validated as floats (using FILTER_VALIDATE_FLOAT). When default is set to option, default's value is used if value is not validated. If we are not going to fix this, this behavior should be documented if it's not already there. So make this a documentation problem? BTW, I haven't test much, but the patch in github invalidates "01", "01.123", etc. Previous Comments: ------------------------------------------------------------------------ [2014-02-16 21:38:26] alex dot howansky at gmail dot com OK, understood. Unfortunately, this leaves an odd hole when working with strings that start with zero and contain an eight or nine. For example, intval() only performs octal validation if you explicitly override the base parameter's default value of 10. As a result, intval('09') gives you exactly what you'd expect -- int(9). Likewise, '09' + 1 works just as expected, in base 10. However, regardless of flags, FILTER_VALIDATE_INT can never return true for string '09'. Given that '09' is perfectly acceptable input for other cases which require an int, this seems inconsistent. Perhaps a new option should be added to this filter, named "base" or similar, which functions like the optional "base" argument of intval(). ------------------------------------------------------------------------ [2014-02-16 19:17:39] rasmus@php.net By definition an integer with a leading zero is octal notation so 00 is octal 0. There is a flag to explicitly allow octal integers which should also tell you that validate_int validates integers written in decimal notation by default. ------------------------------------------------------------------------ [2014-02-16 18:52:55] alex dot howansky at gmail dot com Also, consider this: var_dump(filter_var('0', FILTER_VALIDATE_INT)); var_dump(filter_var('00', FILTER_VALIDATE_INT)); Returns: int(0) bool(false) That's incredibly counter-intuitive. ------------------------------------------------------------------------ [2014-02-16 16:23:03] alex dot howansky at gmail dot com > Please double-check the documentation I'm unable to find any documentation that contradicts my evaluation or explains this behavior. Can you please link to the specific page you're referring to? I'm confused by the hex/oct comment -- whether or not "01" is interpreted as octal or hex doesn't change the fact that it's still a valid value for an integer. I.e., "01" octal is a valid int, "01" hex is a valid int, and "01" decimal is a valid int. Also, if I plug "01" into any other function that expects an integer, it will work just fine. Consider this: var_dump(abs('01')); var_dump(intval('01')); var_dump(octdec('01')); var_dump(hexdec('01')); var_dump(filter_var('01' + '0.0', FILTER_VALIDATE_INT)); var_dump(filter_var('01', FILTER_VALIDATE_INT)); Returns: int(1) int(1) int(1) int(1) int(1) bool(false) Don't you think that output is rather contradictory? ------------------------------------------------------------------------ [2014-02-16 11:55:43] derick@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php This is by design. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=66682 -- Edit this bug report at https://bugs.php.net/bug.php?id=66682&edit=1