Description:
------------
APC stat=off checks require_once requests from cache first without checking if the physical file changed, however, this is not true if the physical file is deleted.

What I did: Set stat=off. Perform apc_compile_file on a php file, then deleted the physical file, then issued require_once to execute the file out of cache. 

Expected results: The php file in the apc cache should have been executed properly using require_once. 

Actual results: When the require_once was issued, a fatal error occurred saying file does not exist, even though it does exist in the apc cache. 

The documentation describes stat=off not checking for changed files, but makes no mention if the file no longer exists. In the spirit of stat=off providing the maximum performance without checking the physical file, this should also include not checking for deleted files as well. If a file in cache needs to be invalidated the appropriate action would be to clear the system cache (for ver 3.0.19) or use the apc_delete_file api(?)(for ver 3.1.1).


Reproduce code:
---------------
index.php file contains:
<?
apc_clear_cache();

echo '<b>require_once after file overwritten</b><br>';
$filename1='/home/apc/public_html/compile1.php';
file_put_contents($filename1,'compile1.php is cached in apc');
apc_compile_file($filename1);
file_put_contents($filename1,'compile1.php file is overwritten');
require_once($filename1);

echo '<br><br><b>require_once after file deleted</b><br>';
$filename2='/home/apc/public_html/compile2.php';
file_put_contents($filename2,'compile2.php is cached in apc');
apc_compile_file($filename2);
unlink($filename2);

print_r(apc_cache_info()); // dump cache before fatal error
require_once($filename2);
?>

You can execute the above code at URL:
http://66.7.210.76/~apc/


Expected result:
----------------
Expected HTTP output:

require_once after file overwritten
compile1.php is cached in apc

require_once after file deleted
(dump of apc cache showing compile1.php and compile2.php reside in the cache)
compile2.php is cached in apc


Actual result:
--------------
Actual HTTP output:

require_once after file overwritten
compile1.php is cached in apc

require_once after file deleted
(dump of apc cache showing compile1.php and compile2.php reside in the cache)
Warning: require_once(/home/apc/public_html/compile2.php) [function.require-once]: failed to open stream: No such file or directory in /home/apc/public_html/index.php on line 18

Fatal error: require_once() [function.require]: Failed opening required '/home/apc/public_html/compile2.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/apc/public_html/index.php on line 18