Bug #72691 [Csd]: mb_ereg_search raises a warning if a match zero-width

Edit report at https://bugs.php.net/bug.php?id=72691&edit=1 ID: 72691 Updated by: cmb@php.net Reported by: ju1ius at laposte dot net Summary: mb_ereg_search raises a warning if a match zero-width Status: Closed Type: Bug Package: mbstring related Operating System: Debian Sid PHP Version: 5.6.24 Assigned To: cmb Block user comment: N Private report: N New Comment: Note that after this fix the actual output still doesn't match the expected output, due to bug #72693 and probably another (yet unreported?) issue ("o" instead of "foo"). Previous Comments: ------------------------------------------------------------------------ [2016-07-28 11:34:52] cmb@php.net Automatic comment on behalf of cmb Revision: http://git.php.net/?p=php-src.git;a=commit;h=d276e6a8386a68d57d5dd07c3d7e15de4b03c6b3 Log: Fix #72691: mb_ereg_search raises a warning if a match zero-width ------------------------------------------------------------------------ [2016-07-28 10:04:13] cmb@php.net Indeed, that warning makes no sense; cf. the behavior of PCRE (see <https://3v4l.org/bHAla>). It has been mistankenly been introduced with the commit <https://github.com/php/php-src/commit/55b5913>. ------------------------------------------------------------------------ [2016-07-28 05:00:12] ju1ius at laposte dot net Description: ------------ when provided a pattern that produces a zero-width match (empty string), mb_ereg_search raises: Warning: mb_ereg_search(): Empty regular expression. First the warning is misleading, since it should not warn about an 'empty regular expression', but about a 'zero-width match'. More importantly this behavior is incorrect. A zero-width result is a perfectly valid match, and should never raise a warning. For example, matching the pattern '\A' at position zero should succeed without a warning, and the resulting position should be zero. Matching pattern '\s*' against the subject 'foo' at position 1 should succeed without a warning and the resulting position should be 1. Test script: --------------- <?php $str = 'foo'; mb_ereg_search_init($str); mb_ereg_search('\A'); var_dump(mb_ereg_search_getpos()); var_dump(mb_ereg_search_getregs()); mb_ereg_search('\s*'); var_dump(mb_ereg_search_getpos()); var_dump(mb_ereg_search_getregs()); mb_ereg_search('\w+'); var_dump(mb_ereg_search_getpos()); var_dump(mb_ereg_search_getregs()); mb_ereg_search('\Z'); var_dump(mb_ereg_search_getpos()); var_dump(mb_ereg_search_getregs()); Expected result: ---------------- int(0) array(1) { [0]=> string(0) "" } int(0) array(1) { [0]=> string(0) "" } int(3) array(1) { [0]=> string(0) "foo" } int(3) array(1) { [0]=> string(0) "" } Actual result: -------------- Warning: mb_ereg_search(): Empty regular expression in ... int(1) array(1) { [0]=> string(0) "" } Warning: mb_ereg_search(): Empty regular expression in ... int(2) array(1) { [0]=> string(0) "" } int(3) array(1) { [0]=> string(1) "o" } Warning: mb_ereg_search(): Empty regular expression in ... int(4) array(1) { [0]=> string(0) "" } ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=72691&edit=1