Bug #62794 [Nab]: print_r with debug_backtrace overwrites member variable

Edit report at https://bugs.php.net/bug.php?id=62794&edit=1 ID: 62794 User updated by: burakg at torreycommerce dot com Reported by: burakg at torreycommerce dot com Summary: print_r with debug_backtrace overwrites member variable Status: Not a bug Type: Bug Package: MySQLi related Operating System: CentOS 6.3 PHP Version: 5.3.15 Block user comment: N Private report: N New Comment: Hey, thanks for taking a look at this. This behavior seems confusing since printing is usually considered a read-only operation on an object. In any case, I am interested in learning about the rationale but I couldn't find the place where it's documented, could you provide a link? Previous Comments: ------------------------------------------------------------------------ [2012-08-11 08:19:26] laruence@php.net Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php when you print_r the mysqli object, it will can a static method of mysql , which also be considered as a operation, if it was executed successful, then empty error info will be set. following method act the same : class Db extends mysqli { function f() { $this->query("select"); var_dump($this->error); print_r($this, true); var_dump($this->error); } } ------------------------------------------------------------------------ [2012-08-10 20:43:12] burakg at torreycommerce dot com Description: ------------ Calling print_r(debug_backtrace()) from a method of a class that inherits from mysqli overwrites the error member variable. Calling debug_backtrace() on its own doesn't seem to cause any problems, but when combined with print_r, this problem results. Test script: --------------- <?php class Db extends mysqli { function f() { $this->query("select"); var_dump($this->error); print_r(debug_backtrace(), true); var_dump($this->error); } } $db = new Db("host", "user", "password", "database"); $db->f(); Expected result: ---------------- string(146) "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1" string(146) "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1" Actual result: -------------- string(146) "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1" string(0) "" ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=62794&edit=1