--- a/UndefinedObject.st	Mon Mar 03 21:12:01 2003 +0100
+++ b/UndefinedObject.st	Mon Mar 03 21:13:50 2003 +0100
@@ -311,6 +311,7 @@
     ^ 0
 ! !
 
+
 !UndefinedObject methodsFor:'subclass creation'!
 
 nilSubclass:action
@@ -551,6 +552,19 @@
     "Modified: / 19.5.1998 / 17:42:10 / cg"
 !
 
+checkNilFileStream
+    "Do nothing if this is a valid FileStream
+     (i.e. the previous open operation was successful).
+     Also implemented in UndefinedObject, to raise an Error there.
+
+     This is an aid for converting from the old error reporting (returning nil)
+     to the new error reporting (with real Exceptions.
+
+     It will vanish as soon as the conversion has been done"
+
+    ^ ExternalStream openErrorSignal raise
+!
+
 hash
     "return an integer useful as a hash key"
 
@@ -665,10 +679,11 @@
 
 ! !
 
+
 !UndefinedObject class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.54 2002-12-10 14:36:26 penk Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.55 2003-03-03 20:13:50 stefan Exp $'
 ! !
 
 UndefinedObject initialize!