Bug #69433 [Ver]: function mb_split incorrectly parsing multibyte strings with mbregex

Edit report at https://bugs.php.net/bug.php?id=69433&edit=1 ID: 69433 Updated by: cmb@php.net Reported by: pffycloud at gmail dot com Summary: function mb_split incorrectly parsing multibyte strings with mbregex Status: Verified Type: Bug Package: mbstring related Operating System: any PHP Version: 5.6.7 Block user comment: N Private report: N New Comment: Basically, the problem is that neither mb_split() nor mb_ereg_replace() properly cater to matches of length 0, so \B is matched at the very start of the subject and also 1 position ahead. Previous Comments: ------------------------------------------------------------------------ [2016-07-31 16:30:05] cmb@php.net > It seems '\B' behaves differently than PCRE. Indeed, and I'd call that difference a bug, see <https://3v4l.org/U3tdm>. ------------------------------------------------------------------------ [2015-04-14 20:19:16] yohgaki@php.net It seems '\B' behaves differently than PCRE. http://3v4l.org/fb4XN ------------------------------------------------------------------------ [2015-04-12 22:34:33] pffycloud at gmail dot com Added Mac OS X 10.10 Yosemite to 'OS' for clarity. ------------------------------------------------------------------------ [2015-04-12 22:33:07] pffycloud at gmail dot com Description: ------------ The multibyte split function (function.mb_split) does not appear to be working as expected. Instead of parsing and converting the multibyte string into array elements as specified, the character elements are being split at unpredictable positions, yielding unpredictable array elements. The "Test script" demonstrates an expected result for the first multibyte string, but then shows unexpected results for the next two multibyte strings. Thank you for reviewing this potential bug. Test script: --------------- <?php header('Content-Type: text/html; charset=UTF-8'); mb_regex_encoding('UTF-8'); mb_internal_encoding('UTF-8'); $arr = mb_split('\B', "你好"); # Array ( [0] => 你 [1] => 好 ) ## Okay! print_r($arr); $arr = mb_split('\B', "你你"); # Array ( [0] => 你 [1] => 你 ) ## Expected Result print_r($arr); ## Instead, this message appears: ## Warning: mb_split(): mbregex search failure in mbsplit(): ## no support in this configuration in /dir/foo.php on line 22 $arr = mb_split('\B', '隨著劇情的推進'); print_r($arr); # Expected Result # Array ( [0] => 隨 [1] => 著 [2] => 劇 [3] => 情 [4] => 的 [5] => 推 [6] => 進 ) # Actual Result, NOT expected # Array ( [0] => 隨 [1] => � [2] => �劇 [3] => � [4] => �的 [5] => � [6] => �進 ) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=69433&edit=1