Bug #53823 [Com]: preg_replace: * qualifier on unicode replace garbles the string

Edit report at https://bugs.php.net/bug.php?id=53823&edit=1 ID: 53823 Comment by: nhahtdh at gmail dot com Reported by: keith at chaos-realm dot net Summary: preg_replace: * qualifier on unicode replace garbles the string Status: Verified Type: Bug Package: PCRE related Operating System: Linux PHP Version: 5.3SVN-2011-01-23 (snap) Block user comment: N Private report: N New Comment: This should be a duplicate to https://bugs.php.net/bug.php?id=66121, since the underlying cause is the same. After matching empty string at the beginning (index 0) and replace it with empty string, the function will try to match at index 0 again but pass a flag to assert non-empty string match, which it obviously fails. Then the function advance the offset by 1 data unit (1 byte in this case) and hilarity ensues. The correct behavior is that when u modifier is used, the function should always advance by code unit (1 UTF character). Previous Comments: ------------------------------------------------------------------------ [2012-02-25 09:54:52] robertbasic dot com at gmail dot com Updated the test case showing that preg_filter and preg_replace_callback are affected, too. ------------------------------------------------------------------------ [2012-02-24 23:33:34] robertbasic dot com at gmail dot com I tried my best on this one. Tested against the trunk: svn info | grep Revision Revision: 323476 I created a test file for this, will attach. I ran the following with gdb: $ gdb sapi/cgi/php-cgi and then set a breakpoint (gdb) break php_pcre.c:1318 finally ran the test script like: (gdb) run run-tests.php ext/pcre/tests/bug53823.phpt On https://gist.github.com/1904467 I c/p-ed some output from gdb, but that might be incorrect as I'm fairly new to all this. Anyway, lines 12 and 22 in that gist caught my attention. Also, I think the same issue exists for preg_filter, too. ------------------------------------------------------------------------ [2011-01-26 08:02:54] aharvey@php.net Verified on 5.3 and trunk. ------------------------------------------------------------------------ [2011-01-23 18:10:44] tino dot didriksen at gmail dot com ...and then I forget to change the *. Let's try that again... These work as expected: echo preg_replace('/[^\pL\pM]+/iu', '', 'áéíóú'); echo preg_replace('/[^\pL\pM\pN]+/iu', '', 'áéíóú'); ------------------------------------------------------------------------ [2011-01-23 18:09:23] tino dot didriksen at gmail dot com A workaround is to use + instead of *. These work as expected: echo preg_replace('/[^\pL\pM]*/iu', '', 'áéíóú'); echo preg_replace('/[^\pL\pM\pN]*/iu', '', 'áéíóú'); ------------------------------------------------------------------------ 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=53823 -- Edit this bug report at https://bugs.php.net/bug.php?id=53823&edit=1