#41375 [Opn]: substr() undocumented behavior change from 5.2.1 to 5.2.2

ID: 41375 Updated by: chagenbu@php.net Reported By: bugs dot php dot net at kreidenweis dot com Status: Open Bug Type: Documentation problem Operating System: Any PHP Version: 5.2.2 New Comment: Okay, documenting it at least makes code and documentation consistent, but why the change in the first place? Why not avoid the break and leave it consistent? Previous Comments: ------------------------------------------------------------------------ [2007-09-07 09:40:38] jani@php.net Reclassified. ------------------------------------------------------------------------ [2007-09-07 06:48:16] pajoye@php.net "If start is negative, the returned string will start at the start'th character from the end of string." The function still accepts a negative start. What changed is if the start is longer than the string length, the test (user friendly version): if (from > strlen(str) || (from < 0 && -from > strlen(str))) As I agree it may break some scripts, the new behavior should be documented, as a bug fix. Can we move this bug to the doc category? ------------------------------------------------------------------------ [2007-09-07 02:22:57] chagenbu@php.net Seems to me as if this was introduced with 5.2.3, not 5.2.2 per the original submitter. Also see http://us.php.net/manual/en/function.substr.php#75999 - this isn't something that only affects me. ------------------------------------------------------------------------ [2007-09-07 02:20:36] chagenbu@php.net I'm sorry, but this is a definite BC break and has bitten me both in Horde code and in my company's codebase. I've re-read the substr docs several times and I don't see any indication that a negative $start can cause substr to return false. Here's the description of the start parameter in its entirety: If start is non-negative, the returned string will start at the start'th position in string, counting from zero. For instance, in the string 'abcdef', the character at position 0 is 'a', the character at position 2 is 'c', and so forth. If start is negative, the returned string will start at the start'th character from the end of string. Example 2454. Using a negative start <?php $rest = substr("abcdef", -1); // returns "f" $rest = substr("abcdef", -2); // returns "ef" $rest = substr("abcdef", -3, 1); // returns "d" ... from http://us3.php.net/substr. ------------------------------------------------------------------------ [2007-05-12 15:47:23] iliaa@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 . ------------------------------------------------------------------------ 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 http://bugs.php.net/41375 -- Edit this bug report at http://bugs.php.net/?id=41375&edit=1