Description:
------------
Env:
Windows XP SP2
Apache 2.0.48 / 2.0.55 (not relevant)
MySQL 5.0.16
PHP 5.0.3 /5.1 (not relevant)
MySQLi

Important: Problem is related to MySQLi when using MySQL version 5 only,
it doesn't occur with version 4.

Reproduce code:
---------------
<?php

$db = new mysqli(...);

if($stmt = $db->prepare('SELECT SUM(visitors) FROM core_stats')) {
    $stmt->execute();
    $stmt->bind_result($total);

    $stmt->close();
}

?>

The problem occurs when using SUM() in query, endless loop seems to
start when $stmt->bind_result($total) is invoked and as a result Apache
crashes.

Database reproduction code:
----------------------------------
CREATE TABLE `core_stats` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `day_of_week` int(1) unsigned NOT NULL default '0',
  `day_of_month` int(2) unsigned NOT NULL default '0',
  `m` int(2) unsigned NOT NULL default '0',
  `y` int(4) unsigned NOT NULL default '0',
  `visitors` int(10) unsigned NOT NULL default '0',
  PRIMARY KEY  (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

INSERT INTO `core_stats` VALUES (1, 2, 5, 7, 2005, 1);
INSERT INTO `core_stats` VALUES (2, 3, 6, 7, 2005, 6);
INSERT INTO `core_stats` VALUES (3, 4, 7, 7, 2005, 7);
INSERT INTO `core_stats` VALUES (4, 5, 8, 7, 2005, 1);

Expected result:
----------------
It should work as it worked on MySQL 4. 

Actual result:
--------------
Internal Server Error

I can't reproduce it.
Can you try it on an *nix OS ?

Unfortunately i cannot reproduce it on unix at the moment (have to
upgrade the mysql), but 
ill gladly provide further information on windows.
hint: it is essential to create a table with content, im not sure if i
provided enough of it;)

You don't have to *upgrade* it, you can install as much MySQL
servers/clients as you want if you place it in different directories.

Im sorry, but i tried for 2 hours and i cant get mysqli to work under
linux, winxp will have to be enough:(

Please try using this CVS snapshot:

  http://snaps.php.net/php5-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5-win32-latest.zip

It's very much likely that this was already fixed.

It seems that whole mysqli code has to be revised, since it still is
very unstable, i think that other queries cause the crashes too, like
some inserts for example...
the SUM crash is not fixed in latest snapshot, and it seems that there r
many more bugs and i still can't get my app to work (its using mysql
heavily), i still get crashes and strange behaviours.
If any developer is willing i can provide him with the code of this app
so he can see what im talking about.
Just write ur e-mail and ill contact u.

Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves. 

A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external 
resources such as databases, etc.

If possible, make the script source available online and provide
an URL to it here. Try to avoid embedding huge scripts into the report.

We're still unable to reproduce it.

Thats the code to reproduce the crash:
http://pl.maze.pl/tmp/test.php.txt
Its used with this table - http://pl.maze.pl/tmp/db_table.sql
But i dont think thats the only piece of code that causes the crash.
just run http://localhost/test.php, then hit f5 and u should encouter
it. (i can be only win platform related)
ill do some further research in the meantime.

Its not happening when using mysql ext, so im pretty sure its mysqli.

Works fine on Linux with MySQL 5.0.13.

Here's there crash itself - http://pl.maze.pl/tmp/crash.jpg
It takes 100% of CPU and then the crash...

As you may understand, the screenshot is not a backtrace and doesn't
help in any way.

Maybe >= 5.0.15 mysql is required? or maybe it is only windows platform
issue.

Yeah, I'd appreciate if you find answers for these questions.

Im not sure how to help You, what else can i do?

1) Try to downgrade MySQL on Windows and see if it changes anything.
2) Try to upgrade MySQL on Linux and see if it changes anything.
This is so obvious, isn't it?

Win:
php 5.0.3 + mysql 4.1.7 - ok
php 5.0.3 + mysql 5.0.16 - crash
php 5.0.5 + mysql 5.0.15 - crash
php 5.1 + mysql 5.0.16 - crash
php 5.1.2-dev + mysql 5.0.16 - crash
php 5.1.2-dev + mysql 4.1.15 - ok
Linux:
php 5.0.5 + mysql 4.1.13 - ok

Thats all I can tell u for now.

These were 3 machines.

I dont know if its relevant, but i get exactly the same gdb backtrace as
here http://bugs.php.net/bug.php?id=35388

Now im sure its irrelevant, sorry.

I forgot i was running mysql 4.1.15:)
The backtrace from php 5.1.2-dev and mysql 5.0.16:

Program received signal SIGSEGV, Segmentation fault.
0x00e654de in ?? ()
(gdb) bt
#0  0x00e654de in ?? ()
#1  0x00000021 in ?? ()
#2  0x00374128 in ?? ()

If you'd install the latest CVS snapshot and the debug symbols, you'd
propably get a bit better backtrace:

  http://snaps.php.net/ 

(c) Jani

What do i do with these *.pdb files?

Extract them? And copy wherever you have the binaries and dlls for each
file..

Assigned to the maintainer.

Please try using this CVS snapshot:

  http://snaps.php.net/php5.1-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php5.1-win32-latest.zip

What's the point of checking the same and unchanged file again?

No, nothing. Don't bother, it's fixed. And reported by dozen other
people too..

Why do you think it's unchanged?
The url is the same, while file is regenerated every time.

The size is unchanged, the bug still exists, so where is the difference?

Can't replicate on latest cvs.

Right, its better to pretend there is no problem, just stick a label
"bogus" and forget.
Why did a have a feeling that u wont care anyway?
In the bug - http://bugs.php.net/bug.php?id=35388, georg might have
given the reason and possible solution for this problem (my client
version is 4.1.7 too).
That could explain why u cant reprocude it.
But its so hard to think...i know...
Its time for u to paste this "Please try using this CVS snapshot:" text,
right?

MySQL client bugs should be reported in another place and they are
obviously not PHP bugs.

But its not the MySQL that crashes, is it?

PDO and mysql extensions somehow dont have problem with different client
versions, everything works fine, why mysqli can't?

Fresh news - ive updated client version to 5.0.16, and the crash still
occurs - only when using mysqli ext.