#37096 [Opn->Fbk]: referencing bug with return value for stream_seek

ID: 37096 Updated by: tony2001@php.net Reported By: wez@php.net -Status: Open +Status: Feedback Bug Type: Streams related Operating System: * PHP Version: 5CVS-2006-04-16 (CVS) New Comment: Thank you for this bug report. To properly diagnose the problem, we need a short but complete example script to be able to reproduce this bug ourselves. A proper reproducing script starts with <?php and ends with ?>, is max. 10-20 lines long and does not require any external resources such as databases, etc. If the script requires a database to demonstrate the issue, please make sure it creates all necessary tables, stored procedures etc. Please avoid embedding huge scripts into the report. Previous Comments: ------------------------------------------------------------------------ [2006-07-26 09:21:28] tendencies at free dot fr See this bug : http://bugs.php.net/bug.php?id=30157 ------------------------------------------------------------------------ [2006-04-16 02:29:02] wez@php.net Description: ------------ When using user-space streams via stream_wrapper_register(), if you return the value of a property of the object from stream_seek(), it gets mangled. Sounds like a problem with the way that the retval from call_user_function_ex() is disposed. The workaround is to create a temporary value using a trick like this: function stream_seek($offset, $whence) { ... $retval = $this->pos + 0; return $retval; } presumably the rest of the user wrapper code has the same flaw. Reproduce code: --------------- Abbreviated example; my actual test case is too large. Valgrind does not indicate any memory errors, so the problem is likely logical rather than sloppy memory handling. class MyStream { var $this->pos = 0; function stream_tell() { return $this->pos; } function stream_seek($offset, $whence) { return $this->pos; } } Actual result: -------------- Problem manifested for me by converting $this->pos to bool(true), which was then interpreted by the user space wrapper as an invalid return value from stream_tell(), which simply returns $this->pos. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=37096&edit=1