diff --git a/core/includes/install.inc b/core/includes/install.inc
index 39b4a02..5400ce0 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -448,17 +448,25 @@ function drupal_install_system() {
  *   TRUE on success or FALSE on failure. A message is set for the latter.
  */
 function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {
+  // If type is not set, we cannot try to set the check function.
+  if (!isset($type)) {
+    return FALSE;
+  }
+  // Use is_file(), is_dir() or is_link() according to the type of file.
+  $check = 'is_' . $type;
+  // If it is not a type we can check for, return.
+  if (!function_exists($check)) {
+    return FALSE;
+  }
+
   $return = TRUE;
   // Check for files that shouldn't be there.
-  if (isset($mask) && ($mask & FILE_NOT_EXIST) && is_file($file)) {
+  if (isset($mask) && ($mask & FILE_NOT_EXIST) && $check($file)) {
     return FALSE;
   }
   // Verify that the file is the type of file it is supposed to be.
-  if (isset($type) && is_file($file)) {
-    $check = 'is_' . $type;
-    if (!function_exists($check) || !$check($file)) {
-      $return = FALSE;
-    }
+  if (!$check($file)) {
+    return FALSE;
   }
 
   // Verify file permissions.
@@ -468,11 +476,11 @@ function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {
       if ($mask & $current_mask) {
         switch ($current_mask) {
           case FILE_EXIST:
-            if (!is_file($file)) {
+            if (!$check($file)) {
               if ($type == 'dir') {
                 drupal_install_mkdir($file, $mask);
               }
-              if (!is_file($file)) {
+              if (!$check($file)) {
                 $return = FALSE;
               }
             }
@@ -577,8 +585,11 @@ function drupal_install_mkdir($file, $mask, $message = TRUE) {
  *  TRUE/FALSE whether or not we were able to fix the file's permissions.
  */
 function drupal_install_fix_file($file, $mask, $message = TRUE) {
+  // Use file_exists() since with will return true also for directories and
+  // these checks are should be done for any type: file, dir, link.
+
   // If $file does not exist, fileperms() issues a PHP warning.
-  if (!is_file($file)) {
+  if (!file_exists($file)) {
     return FALSE;
   }
 
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index 8dbb5a7..64e6169 100644
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -575,6 +575,6 @@
  *
  * Keep this code block at the end of this file to take full effect.
  */
-# if (file_exists(DRUPAL_ROOT . '/' . $conf_path . '/settings.local.php')) {
+# if (is_file(DRUPAL_ROOT . '/' . $conf_path . '/settings.local.php')) {
 #   include DRUPAL_ROOT . '/' . $conf_path . '/settings.local.php';
 # }