ID: 49207 Updated by: scott...@php.net Reported By: ronlentjes at yahoo dot com dot au Status: Feedback Bug Type: Scripting Engine problem Operating System: Linux Fedora 8 PHP Version: 5.3.0 New Comment:
Works for me in 5.3.0 <?php $n = 2147483647; $n = (int) ($n + 1); var_dump($n); $n = (int) ($n - 1); var_dump($n); ?> Produces int(-2147483648) int(2147483647) Previous Comments: ------------------------------------------------------------------------ [2009-08-10 10:35:12] j...@php.net Exactly what version produces correct result (in your opinion) and _exactly_ what version does not? ------------------------------------------------------------------------ [2009-08-10 10:13:02] ronlentjes at yahoo dot com dot au Description: ------------ Old version are correct. Eg 4.2.2 is exhibiting correct integer behavior. Wrapping issue. All tests on 40 other languages pass according to this simple test: Ver 4.2.2 $n = 2147483647; $n = (int) ($n + 1) -> -2147483648 (+wrap, correct) $n = (int) ($n - 1) -> 2147483647 (-wrap, correct) (C/C++/C#/.../assembly inc,dec/perl(int mode)/python/so on follow this logic) Ver 5.2.4 $n = 2147483647; $n = (int) ($n + 1) -> -2147483648 (+wrap, correct) $n = (int) ($n - 1) -> -2147483648 (-max, wrong) (no other language follow this. Some languages do use +/-max but not this mix of wrap one way and max the other) Suggest: back to original +/- wrapping. Your newer versions are wrong. You wrap going positive around the integer wheel. You don't wrap going negative around the integer wheel. One direction you wrap, the other direction you do a max. I test all languages and this is incorrect integer behavior. Your original logic was correct but now broken and affects all original source code. Related issue by someone else: #30315. Got closed but core issue misunderstood. Cheers, Ron Lentjes, LC CLS. Reproduce code: --------------- Sorry, didn't see these boxes. See above. Your version is irrelavent here as I am talking about a change from old to new versionS. New ones don't work. (I could not select irrelavent so just chose one on list - but that's not the point). ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=49207&edit=1
