ID: 40967
User updated by: Webbed dot Pete at gmail dot com
-Summary: 500 Server Error on array_merge of func return
Reported By: Webbed dot Pete at gmail dot com
Status: Open
Bug Type: Reproducible crash
Operating System: Linux
PHP Version: 5.2.1
New Comment:
[To answer your question directly: the getarray() function retrieves an
array from an in-memory global cache var]
Actually, the getarray() function is immaterial; it's never called when
the system is set in "crash mode". I put a debug trace-to-file on the
line before and after the array_merge() call, and also as the first
element of the getarray() function. The debug trace inside getarray() is
never called while getarray() is embedded in the array_merge() call.
Now the good-yet-a-bit-frustrating news: we've resolved this issue, in
an unusual way. The solution may be informative to other hard to
track-down bugs.
Bottom line: the array_merge() problem went away when our webhost
company rebuilt the custom php5 cgi script that runs php5 in the
phpSuExec environment! How the execution environment can have any impact
on array_merge() is beyond me, but that's the facts.
How we found this. Told here for the benefit of others who may find
similarly troubling issues:
I discovered another 500 error that *did* point to execution
environment (crash on chdir() with 100% perfect permissions) and
reported it to our sitehost tech support, who escalated it to top tier
support.
The chdir() crash was recognized as a phpSuExec issue, specifically "a
problem with our php5 cgi script that launches PHP5 with custom
configuration options which resulted in premature end of script headers
errors."
Unfortunately, the corrupted cgi script was not saved for analysis.
They simply ran their rebuild-php5-environment script, overwriting the
whole thing.
In retrospect, they suspect an update to cPanel may have corrupted the
script. The conversation continues: if an update did this, then perhaps
other servers in their farm have the same problem and can be diff'd with
mine. They don't keep backups of these scripts since they can be
auto-gen'd.
I hope that helps! I'm still amazed that *anything* in the execution
environment can impact the operation of something as benign as
array_merge().
Pete
Previous Comments:
------------------------------------------------------------------------
[2007-04-01 22:51:22] judas dot iscariote at gmail dot com
Then tell use what the.. the getarray() function does **exactly**
------------------------------------------------------------------------
[2007-03-31 15:06:34] Webbed dot Pete at gmail dot com
Description:
------------
If I do
{
$from=getarray();
$tgt=array_merge($to,$from);
}
all is well. But if I do
{
$tgt=array_merge($to,getarray());
}
then the page blows up with a 500 internal server error (and getarray()
is never called).
I can't (yet) duplicate this as a simple test case; it only happens in
the middle of a large site source base.
This is on an Apache server (1.3.37) with PHP 5.2.1 running as CGI.
The *really* painful part is the 500 Internal Server Error, with no PHP
error messages of any kind. Made it incredibly painful to track this
down ;)
Reproduce code:
---------------
See above. I've not yet got a simple test case. All of the following
produce the 500 error:
$tgt=array_merge($to,getarray());
$tgt=array_merge($to,$from=getarray());
$tgt=array_merge($to,(array)getarray());
Only if the getarray() call is outside the array_merge() does it
succeed.
Expected result:
----------------
a) No error
b) Better debugability of 500 Internal Server Errors caused by PHP
Actual result:
--------------
500 Internal Server Error with no other message.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=40967&edit=1
