Description:
------------
For a complete description of this bug, please see this 
topic: http://groups.google.com/group/mongodb-
user/browse_thread/thread/be07a66d75368f76

Basically, I got a segmentation fault when running a piece 
of code using a foreach loop on a mongodb cursor, which I 
first believed to be a mongodb php driver issue. However, 
when running my php script with the gnu debugger, here is 
what I got:

Program received signal SIGSEGV, Segmentation fault. 
_php_ibm_db2_conn (le=0x12aa920) at /home/xavier/temp/php-
5.3.7/ext/ 
ibm_db2/ibm_db2.c:645 
645             if (conn_res->flag_transaction == 1) { 
(gdb) bt 
#0  _php_ibm_db2_conn (le=0x12aa920) at 
/home/xavier/temp/php-5.3.7/ 
ext/ibm_db2/ibm_db2.c:645 
#1  0x00000000007cc1b5 in zend_hash_apply (ht=0xfa78b8, 
apply_func=0x576090 <_php_ibm_db2_conn>) at 
/home/xavier/temp/ 
php-5.3.7/Zend/zend_hash.c:674 
#2  0x0000000000571e3e in zm_deactivate_ibm_db2 (type=<value 
optimized 
out>, module_number=<value optimized out>) at 
/home/xavier/temp/ 
php-5.3.7/ext/ibm_db2/ibm_db2.c:663 
#3  0x00000000007c16ac in module_registry_cleanup (module=
<value 
optimized out>) at /home/xavier/temp/php-
5.3.7/Zend/zend_API.c:2168 
#4  0x00000000007cc084 in zend_hash_reverse_apply 
(ht=0xfa7ec0, 
apply_func=0x7c1690 <module_registry_cleanup>) at 
/home/xavier/temp/ 
php-5.3.7/Zend/zend_hash.c:757 
#5  0x00000000007c00dd in zend_deactivate_modules () at 
/home/xavier/ 
temp/php-5.3.7/Zend/zend.c:867 
#6  0x000000000076c945 in php_request_shutdown (dummy=<value 
optimized 
out>) at /home/xavier/temp/php-5.3.7/main/main.c:1614 
#7  0x0000000000849478 in main (argc=<value optimized out>, 
argv=<value optimized out>) at /home/xavier/temp/php-
5.3.7/sapi/cli/ 
php_cli.c:1363 


So it seems that the ibm_db2 driver is stomping on memory 
used by others php extensions.

		
Kristina Chodorow helped me with this issue and wrote :

"PHP keeps a list of persistent bits of memory that is 
shared by all 
extensions.  The DB2 extension is going through the entire 
list and treating 
everything as a struct allocated by DB2.  However, the Mongo 
extension uses 
that list, too!  DB2 is trying to destroy all of Mongo's 
persistent structs 
at the end of each request.  You could file a bug with the 
DB2 extension, I 
don't know how active development is. 
You might also be able to fix it yourself by adding: 
if (le->type != le_pconn_struct) { 
  return ZEND_HASH_APPLY_KEEP; 
} 

right before the line that segfaulted ( if (conn_res-
>flag_transaction == 1) 
{ ), so you'd end up with: 
static int _php_ibm_db2_conn (zend_rsrc_list_entry *le 
TSRMLS_DC) 
{ 
    conn_handle *conn_res; 
    int rc = 0; 
    conn_res = (conn_handle *) le->ptr; 
    if (le->type != le_pconn_struct) { 
        return ZEND_HASH_APPLY_KEEP; 
    } 
    if (conn_res->flag_transaction == 1) { 
        conn_res->flag_transaction = 0; 
        if( conn_res->handle_active && conn_res-
>flag_pconnect ) { 
in ibm_db2.c.  This makes DB2 only destroy structs DB2 
'owns'. "


I did the modification in the ibm_db2.c file, and it did the 
trick, now it works fine.  I guess this should be added in a 
next release of the ibm_db2 driver.

About my configuration: I am using php 5.3.7 (but got 
exactly the same issue with 5.3.6), ibm_db2 php driver 
1.9.1, mongodb php driver 1.2.4, os : ubuntu 10.04 LTS.

Hope this could help.

Reproduce code:
---------------
Please see topic here : 
http://groups.google.com/group/mongodb-user/browse_thread/thread/be07a66d75368f76

Expected result:
----------------
Just a code that runs fine without any segmentation fault