Edit report at https://bugs.php.net/bug.php?id=54007&edit=1
ID: 54007
Comment by: brandonkirsch at gmail dot com
Reported by: ken at focusschoolsoftware dot com
Summary: odbc seg faults with null data returned from DB2
Status: Open
Type: Bug
Package: ODBC related
Operating System: Linux
PHP Version: 5.3.5
Block user comment: N
Private report: N
New Comment:
Hi friends,
I have a fix for this problem, which is caused by some rich history in the written standard for
ODBC. IBM's "64-bit" ODBC drivers are written against an older specification, and
they are affected by changes in the size of SQLLEN / SQLULEN types as the specification has evolved.
The "correct" solution for this problem is for IBM to release iSeriesAccess ODBC drivers
that fit the modern specification for 64-bit ODBC.
A workaround that we successfully used in production for several years includes casting certain
64-bit ODBC values down to 32-bits when comparing for SQL_NULL_DATA. It essentially changes PHP to
conform to an outdated ODBC spec that IBM requires. It doesn't break other "real"
64-bit ODBC drivers as long as you aren't pulling back individual values > 4GB.
I'll re-iterate that PHP is using the correct specification for 64-bit ODBC, so this is *NOT* a
bug. But if you need compatibility with IBM in a 64-bit environment, you can have / study / re-use
the workaround I developed and posted at http://perceptionilluminates.com/php/php_odbc.c
Previous Comments:
------------------------------------------------------------------------
[2012-10-19 12:16:09] tuomas dot angervuori at gmail dot com
Seems that this bug is somehow 64bit related. I get segmentation fault on my
64bit ubuntu 12.04 (php-5.3.10 & IBM i Access 7.1) but not with 32bit Debian
(php-5.3.3 & IBM i Access 7.1).
I can do more tests & provide more detailed information if needed.
------------------------------------------------------------------------
[2011-11-10 09:38:10] giuseppe at blandino dot it
I've the same problem.
I'm trying to migrate my web applications from an old Ubuntu server 64bit with PHP 5.2.4 and
DB2 9.1.0 to a new Ubuntu 10.4 LTS 64 bit server with PHP Version 5.3.2-1ubuntu4.10, Apache/2.2.14
and DB2 ver. 9.7.4.
This is a sample of code:
$sql = "SELECT field FROM table WHERE ...";
$result = odbc_exec($id_connect, $sql);
if (odbc_fetch_row($result)) {
$field = (int) odbc_result($result,"field");
// seg fault when field is null
}
But if I try this:
$sql = "SELECT field FROM table WHERE ...";
$result = odbc_exec($id_connect, $sql);
odbc_result_all($result);
it don't crash but give:
<table><tr><th>FIELD</th></tr>
<tr><td>vÃN
â\UJõÃseõº \Å Å+ŽT9</td></tr></table>
It seems that when field is null the ODBC driver return the pointer of somewhere in the memory...
------------------------------------------------------------------------
[2011-07-22 15:19:53] hborrel at gmail dot com
We have the same problem.
As a work around we've had to add this to any feild that may return a NULL.
COALESCE(CHAR(DELIVERYDATE), '')
------------------------------------------------------------------------
[2011-02-13 19:07:17] ken at focusschoolsoftware dot com
FYI:
php_odbc.c:2158 -> RETURN_STRINGL(result->values[field_ind].value, result-
>values[field_ind].vallen, 1);
------------------------------------------------------------------------
[2011-02-13 19:05:10] ken at focusschoolsoftware dot com
Backtrace:
#0 0x00007ffff6879ea1 in memcpy () from /lib/libc.so.6
#1 0x00000000006af648 in _estrndup (s=0x7ffff57cd4b8 "",
length=<value optimized out>) at /usr/include/bits/string3.h:52
#2 0x00007ffff5edadcb in zif_odbc_result (ht=<value optimized out>,
return_value=0x7ffff57d6940, return_value_ptr=<value optimized out>,
this_ptr=<value optimized out>, return_value_used=<value optimized out>,
tsrm_ls=0xc91090)
at /home/focus/Development/php-5.3.5/ext/odbc/php_odbc.c:2158
#3 0x000000000072730d in zend_do_fcall_common_helper_SPEC (
execute_data=0x7ffff7ed39a0, tsrm_ls=0xc91090)
at /home/focus/Development/php-5.3.5/Zend/zend_vm_execute.h:316
#4 0x00000000006f927b in execute (op_array=0xeeb010, tsrm_ls=0xc91090)
at /home/focus/Development/php-5.3.5/Zend/zend_vm_execute.h:107
#5 0x00000000006cec48 in zend_execute_scripts (type=<value optimized out>,
tsrm_ls=0xc91090, retval=<value optimized out>, file_count=3)
at /home/focus/Development/php-5.3.5/Zend/zend.c:1194
#6 0x0000000000670e2d in php_execute_script (
primary_file=<value optimized out>, tsrm_ls=<value optimized out>)
at /home/focus/Development/php-5.3.5/main/main.c:2265
#7 0x0000000000767abe in main (argc=<value optimized out>,
argv=<value optimized out>)
at /home/focus/Development/php-5.3.5/sapi/cli/php_cli.c:1193
------------------------------------------------------------------------
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