--- a/AbstractOperatingSystem.st	Tue Nov 29 15:08:53 2016 +0100
+++ b/AbstractOperatingSystem.st	Tue Nov 29 16:01:22 2016 +0100
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 1988 by Claus Gittinger
 	      All Rights Reserved
@@ -3237,7 +3239,7 @@
 !
 
 truncateFile:aPathName to:newSize
-    "change a files size return true on success, false on failure.
+    "change a files size return nil on success, an OSErrorHolder on failure.
      This may not be supported on all architectures.
 
      This is a low-level entry - use Filename protocol."
@@ -3288,8 +3290,8 @@
 changeAccessModeOf:aPathName to:modeBits
     "change the access rights of aPathName to the OS dependent modeBits.
      You should construct this mask using accessMaskFor, to be OS
-     independent. Return true if changed,
-     false if such a file does not exist or change was not allowd."
+     independent. Return nil if changed,
+     anOSErrorHolder if such a file does not exist or change was not allowd."
 
     self subclassResponsibility
 !