From bbf467babde690cf9f074a916d11313f677b2606 Mon Sep 17 00:00:00 2001
From: David Hedberg <david.hedberg@zavann.se>
Date: Fri, 2 Jun 2017 09:58:28 +0200
Subject: [PATCH] SFTP: Add
 enablePathCanonicalization()/disablePathCanonicalization()

---
 phpseclib/Net/SFTP.php | 47 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/phpseclib/Net/SFTP.php b/phpseclib/Net/SFTP.php
index 40c97daf..7665482d 100644
--- a/phpseclib/Net/SFTP.php
+++ b/phpseclib/Net/SFTP.php
@@ -199,7 +199,7 @@ class Net_SFTP extends Net_SSH2
      * Current working directory
      *
      * @var string
-     * @see self::_realpath()
+     * @see self::realpath()
      * @see self::chdir()
      * @access private
      */
@@ -277,6 +277,20 @@ class Net_SFTP extends Net_SSH2
      */
     var $sortOptions = array();
 
+    /**
+     * Canonicalization Flag
+     *
+     * Determines whether or not paths should be canonicalized before being
+     * passed on to the remote server.
+     *
+     * @see self::enablePathCanonicalization()
+     * @see self::disablePathCanonicalization()
+     * @see self::realpath()
+     * @var bool
+     * @access private
+     */
+    var $canonicalize_paths = true;
+
     /**
      * Default Constructor.
      *
@@ -630,6 +644,26 @@ class Net_SFTP extends Net_SSH2
         $this->stat_cache = array();
     }
 
+    /**
+     * Enable path canonicalization
+     *
+     * @access public
+     */
+    function enablePathCanonicalization()
+    {
+        $this->canonicalize_paths = true;
+    }
+
+    /**
+     * Enable path canonicalization
+     *
+     * @access public
+     */
+    function disablePathCanonicalization()
+    {
+        $this->canonicalize_paths = false;
+    }
+
     /**
      * Returns the current directory name
      *
@@ -688,13 +722,20 @@ class Net_SFTP extends Net_SSH2
      * SFTP doesn't provide a mechanism by which the current working directory can be changed, so we'll emulate it.  Returns
      * the absolute (canonicalized) path.
      *
+     * If canonicalize_paths has been disabled using disablePathCanonicalization(), $path is returned as-is.
+     *
      * @see self::chdir()
+     * @see self::disablePathCanonicalization()
      * @param string $path
      * @return mixed
      * @access private
      */
     function _realpath($path)
     {
+        if (!$this->canonicalize_paths) {
+            return $path;
+        }
+
         if ($this->pwd === false) {
             // http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#section-8.9
             if (!$this->_send_sftp_packet(NET_SFTP_REALPATH, pack('Na*', strlen($path), $path))) {
@@ -1349,7 +1390,7 @@ class Net_SFTP extends Net_SSH2
     /**
      * Returns general information about a file or symbolic link
      *
-     * Determines information without calling Net_SFTP::_realpath().
+     * Determines information without calling Net_SFTP::realpath().
      * The second parameter can be either NET_SFTP_STAT or NET_SFTP_LSTAT.
      *
      * @param string $filename
@@ -1510,7 +1551,7 @@ class Net_SFTP extends Net_SSH2
             return true;
         }
 
-        $filename = $this->_realPath($filename);
+        $filename = $this->realpath($filename);
         // rather than return what the permissions *should* be, we'll return what they actually are.  this will also
         // tell us if the file actually exists.
         // incidentally, SFTPv4+ adds an additional 32-bit integer field - flags - to the following: