Description:
------------
Docs for chmod state:
"When safe mode is enabled, PHP checks whether the files ... you are about to operate on have the same UID (owner) as the script that is being executed"

On a shared user server with php installed as an apache module and safe_mode on, php is running as 'www'. My script script.php (owner uid = 8612) operates on myfile.txt (owner uid = 8612) with fopen() and chmod(). Only fopen works, chmod triggers a "Not owner" warning:

ls -al:
-rwxrwxrwx   1 user1   users   4427 Jul 11 02:38 script.php
-rwxrwxrwx   1 user1   users    282 Jul  8 05:13 myfile.txt

(directory holding these is:
drwxrwxrwx+  2 user1   users    512 Jul 11 02:38 public_html)

Clearly both the script and the file the script operates on have the same owner.

I know (or suspect) this is not a bug in php but rather a side effect of the apache user (www) chmod'ing a file it doesn't own. If so perhaps the docs could be updated to mention this behaviour? chmod in particular spits out a "Not owner" warning and clearly this can cause needless confusion with the above ls -al output.

Reproduce code:
---------------
script.php:
<?php
error_reporting(E_ALL);
$file = "myfile.txt";
echo "fileowner($file) = ".fileowner($file)."\n";
echo "fileowner(".basename(__FILE__).") = ".fileowner(__FILE__)."\n";

$fp = fopen($file,'r');

if(is_resource($fp)) {
	echo "fopen($file) successful\n";
	fclose($fp);
} else {
	echo "fopen($file) failed\n";
}

chmod($file,0755);
?>

Expected result:
----------------
fileowner(myfile.txt) = 8612
fileowner(script.php) = 8612
fopen(myfile.txt) successful

Actual result:
--------------
fileowner(myfile.txt) = 8612
fileowner(script.php) = 8612
fopen(myfile.txt) successful
Warning: chmod(): Not owner in /home/user1/public_html/script.php on line 15