commit 0808b9997886c6d0afd4c45b0bbf743aae5303d6
Author: Antoine Beaupré <anarcat@koumbit.org>
Date:   Sun May 15 20:46:33 2011 -0400

    1158510 dereference site paths in comparisons so we find the site-dir correctly

diff --git a/commands/pm/pm.drush.inc b/commands/pm/pm.drush.inc
index d39cb0e..45a4f5f 100644
--- a/commands/pm/pm.drush.inc
+++ b/commands/pm/pm.drush.inc
@@ -1657,7 +1657,7 @@ function pm_dl_destination($type) {
 
   $in_site_directory = FALSE;
   // Check if we are running within the site directory.
-  if ($full_site_root == substr(drush_cwd(), 0, strlen($full_site_root)) || (drush_get_option('use-site-dir', FALSE))) {
+  if ($full_site_root == substr(realpath(drush_cwd()), 0, strlen(realpath($full_site_root))) || (drush_get_option('use-site-dir', FALSE))) {
     $in_site_directory = TRUE;
   }