From:             j at pureftpd dot org
Operating system: Any
PHP version:      5.2.0
PHP Bug Type:     Filesystem function related
Bug description:  symbolic links should not be inserted into the realpath cache

Description:
------------
realpath() on a symlink returns the final file the link 
points to.

Caching symbolic links through the realpath cache can cause 
unexpected behaviors.

Here's a fix against PHP 5.2.0

--- TSRM/tsrm_virtual_cwd.c.orig        Sat Nov  4 00:56:05 
2006
+++ TSRM/tsrm_virtual_cwd.c     Sat Nov  4 00:58:03 2006
@@ -562,7 +562,11 @@
        }
 
        if (use_realpath && CWDG(realpath_cache_size_limit)) 
{
-               realpath_cache_add(path, path_length, state-
>cwd, state->cwd_length, t TSRMLS_CC);
+               struct stat buf;
+               
+               if (lstat(path, &buf) == 0 && !S_ISLNK
(buf.st_mode)) {          +                       
realpath_cache_add(path, path_length, state->cwd, state-
>cwd_length, t TSRMLS_CC);
+               }
        }
 
        if (verify_path && verify_path(state)) {


Reproduce code:
---------------
See bug #36555, or that code :

<?php

@unlink('/tmp/1link');
@unlink('/tmp/1tmp');
@unlink('/tmp/testfile1');

file_put_contents('/tmp/testfile1', '42');
symlink('/tmp/testfile1', '/tmp/1tmp');
rename('/tmp/1tmp', '/tmp/1link');
$a = file_get_contents('/tmp/1link');
var_dump($a);

unlink('/tmp/1link');

clearstatcache();
$a = file_get_contents('/tmp/1link');
var_dump($a);

?>

Expected result:
----------------
The second file_get_contents() should fail because /tmp/1link 
has been unlinked.

But it doesn't.

Actual result:
--------------
42
42


-- 
Edit bug report at http://bugs.php.net/?id=39367&edit=1
-- 
Try a CVS snapshot (PHP 4.4): 
http://bugs.php.net/fix.php?id=39367&r=trysnapshot44
Try a CVS snapshot (PHP 5.2): 
http://bugs.php.net/fix.php?id=39367&r=trysnapshot52
Try a CVS snapshot (PHP 6.0): 
http://bugs.php.net/fix.php?id=39367&r=trysnapshot60
Fixed in CVS:                 http://bugs.php.net/fix.php?id=39367&r=fixedcvs
Fixed in release:             
http://bugs.php.net/fix.php?id=39367&r=alreadyfixed
Need backtrace:               http://bugs.php.net/fix.php?id=39367&r=needtrace
Need Reproduce Script:        http://bugs.php.net/fix.php?id=39367&r=needscript
Try newer version:            http://bugs.php.net/fix.php?id=39367&r=oldversion
Not developer issue:          http://bugs.php.net/fix.php?id=39367&r=support
Expected behavior:            http://bugs.php.net/fix.php?id=39367&r=notwrong
Not enough info:              
http://bugs.php.net/fix.php?id=39367&r=notenoughinfo
Submitted twice:              
http://bugs.php.net/fix.php?id=39367&r=submittedtwice
register_globals:             http://bugs.php.net/fix.php?id=39367&r=globals
PHP 3 support discontinued:   http://bugs.php.net/fix.php?id=39367&r=php3
Daylight Savings:             http://bugs.php.net/fix.php?id=39367&r=dst
IIS Stability:                http://bugs.php.net/fix.php?id=39367&r=isapi
Install GNU Sed:              http://bugs.php.net/fix.php?id=39367&r=gnused
Floating point limitations:   http://bugs.php.net/fix.php?id=39367&r=float
No Zend Extensions:           http://bugs.php.net/fix.php?id=39367&r=nozend
MySQL Configuration Error:    http://bugs.php.net/fix.php?id=39367&r=mysqlcfg

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