Bug #68370 [Fbk->Opn]: "unset($this)" can make the program crash

Edit report at https://bugs.php.net/bug.php?id=68370&edit=1 ID: 68370 User updated by: drewparoski at gmail dot com Reported by: drewparoski at gmail dot com Summary: "unset($this)" can make the program crash -Status: Feedback +Status: Open Type: Bug Package: Reproducible crash Operating System: CentOS Linux 6.3 PHP Version: 5.6.2 Block user comment: N Private report: N New Comment: Backtrace (PHP 5.5.8): #0 0x00000000006dcc11 in gc_zval_possible_root (zv=0x7ffff7fd9b70) at /home/user/php-5.5.8/Zend/zend_gc.c:143 #1 0x00000000006ca03b in zend_hash_destroy (ht=0x7ffff7fdd288) at /home/user/php-5.5.8/Zend/zend_hash.c:560 #2 0x00000000006bbccb in _zval_dtor_func (zvalue=0x7ffff7fd9b10) at /home/user/php-5.5.8/Zend/zend_variables.c:45 #3 0x00000000006ae170 in _zval_dtor (zvalue=0x7ffff7fd9b10) at /home/user/php-5.5.8/Zend/zend_variables.h:35 #4 i_zval_ptr_dtor (zval_ptr=0x7ffff7fd9b10) at /home/user/php-5.5.8/Zend/zend_execute.h:81 #5 _zval_ptr_dtor (zval_ptr=<optimized out>) at /home/user/php-5.5.8/Zend/zend_execute_API.c:426 #6 0x00000000006cbe4c in zend_hash_del_key_or_index ( ht=0xdd9d28 <executor_globals+360>, arKey=<optimized out>, nKeyLength=<optimized out>, h=<optimized out>, flag=<optimized out>) at /home/user/php-5.5.8/Zend/zend_hash.c:532 #7 0x00000000006ad9ae in zend_delete_variable (ex=0x0, ht=0xdd9d28 <executor_globals+360>, name=0x7ffff7ec91b8 "x", name_len=2, hash_value=5863869) at /home/user/php-5.5.8/Zend/zend_execute_API.c:1687 #8 0x000000000073d5ef in ZEND_UNSET_VAR_SPEC_CV_UNUSED_HANDLER ( execute_data=0x7ffff7fa6160) at /home/user/php-5.5.8/Zend/zend_vm_execute.h:38539home/user #9 0x000000000072ff50 in execute_ex (execute_data=0x7ffff7fa6160) at /home/user/php-5.5.8/Zend/zend_vm_execute.h:363 #10 0x00000000006bbff9 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /home/user/php-5.5.8/Zend/zend.c:1316 #11 0x000000000065dde9 in php_execute_script (primary_file=0x7fffffffddc0) at /home/user/php-5.5.8/main/main.c:2506 #12 0x000000000076c7ec in do_cli (argc=2, argv=0xddc090) at /home/user/php-5.5.8/sapi/cli/php_cli.c:994 #13 0x000000000076cf88 in main (argc=2, argv=0xddc090) at /home/user/php-5.5.8/sapi/cli/php_cli.c:1378 Previous Comments: ------------------------------------------------------------------------ [2014-11-07 13:18:57] aharvey@php.net Thank you for this bug report. To properly diagnose the problem, we need a backtrace to see what is happening behind the scenes. To find out how to generate a backtrace, please read http://bugs.php.net/bugs-generating-backtrace.php for *NIX and http://bugs.php.net/bugs-generating-backtrace-win32.php for Win32 Once you have generated a backtrace, please submit it to this bug report and change the status back to "Open". Thank you for helping us make PHP better. ------------------------------------------------------------------------ [2014-11-07 09:06:06] drewparoski at gmail dot com Description: ------------ Doing "unset($this);" inside a non-static method can make the program crash. I provided an example that crashes on PHP 5.3.0 - 5.6.2. Test script: --------------- <?php class C { public function test() { unset($this); return get_defined_vars(); } } $c = new C(); $x = $c->test(); unset($c, $x); echo "Done\n"; Expected result: ---------------- Done Actual result: -------------- Segmentation fault ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=68370&edit=1