Description:
------------
Hi,

ibm_db2 package causes Apache "segmentation fault(11)" after a reload or graceful restart (not normal restart) when a script contain functions related to gzip compression [gzencode / ob_start('ob_gzhandler')]

ibm_db2 without gz function => no problem
gz function without ibm_db2 => no problem

Config:
openSUSE Leap 42.1 (x64)
Apache 2.4
PHP 7.0.12
package ibm_db2 1.9.9 (or 1.9.8)
Db2 Connect v10.5.0.3 64b

only 2 PHP mods for my test script: 
ibm_db2.so
zlib.so

ini interesting values for my test script:
zlib.output_compression = Off
output_buffering = 4096 or highest
memory_limit = 128M or highest
opcache.enable=0

gdb backtrace shows that my test script invades many apache child processes (server-status confirm that)

One child process executing my script only shows this :
#0  0x00007faee5ecf407 in ?? ()
#1  0x00007faee63d047a in ?? ()
#2  0x00000000ffffffff in ?? ()
#3  0x0000000000000001 in ?? ()
#4  0x00007faee65e4998 in ?? ()
#5  0x00007faee6eaa4e0 in ?? ()
#6  0x0000000000000080 in ?? ()
#7  0x0000000000000000 in ?? ()

Test script:
---------------
<?php
echo $gz = gzencode('foo');
?>

OR

<?php
ob_start('ob_gzhandler');
?>


Expected result:
----------------
Expected result : no Apache crash on apache reload or graceful restart.

Actual result:
--------------
Actual result is Apache "[core:notice] [pid xxxxx] AH00052: child pid xxxxx exit signal Segmentation fault (11)" when using ob_start('ob_gzhandler')
Apache is crashed.

Actual result is Apache "PHP Fatal error:  Maximum execution
time of 30 seconds exceeded in Unknown on line 0" when using gzencode()
Apache is crashed.

Thanks,
Regards.