--- a/UndefinedObject.st	Mon Feb 24 21:02:10 2014 +0100
+++ b/UndefinedObject.st	Mon Feb 24 21:02:31 2014 +0100
@@ -108,6 +108,7 @@
     "Modified: 3.1.1997 / 15:06:15 / cg"
 ! !
 
+
 !UndefinedObject class methodsFor:'queries'!
 
 canBeSubclassed
@@ -154,6 +155,7 @@
 
 
 
+
 !UndefinedObject methodsFor:'converting'!
 
 asBoolean
@@ -212,7 +214,6 @@
     ^ self
 ! !
 
-
 !UndefinedObject methodsFor:'dependents access'!
 
 addDependent:someObject
@@ -237,7 +238,6 @@
     "ignored here - nil has no dependents"
 ! !
 
-
 !UndefinedObject methodsFor:'error catching'!
 
 basicAt:index
@@ -299,6 +299,7 @@
     ^ 0
 ! !
 
+
 !UndefinedObject methodsFor:'subclass creation'!
 
 nilSubclass:action
@@ -516,6 +517,17 @@
     "Modified: / 19.5.1998 / 17:39:36 / cg"
 !
 
+?+ aOneArgBlock
+     "a syntactic sugar-piece:
+      aOneArgBlock is executed with self as argument
+      if self is not nil.
+
+      Note: this method should never be redefined in classes other than UndefinedObject.
+     "
+
+    ^ self
+!
+
 ?? defaultValue
      "a syntactic sugar-piece:
       much like ?, but sends value to the argument if required.
@@ -564,7 +576,7 @@
 
      It will vanish as soon as the conversion has been done"
 
-    ^ ExternalStream openErrorSignal raise
+    ^ OpenError raise
 !
 
 hash
@@ -698,14 +710,16 @@
     ^ aVisitor visitNilWith:aParameter
 ! !
 
+
+
 !UndefinedObject class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.75 2014-02-05 19:09:07 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.76 2014-02-24 20:02:31 stefan Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.75 2014-02-05 19:09:07 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/UndefinedObject.st,v 1.76 2014-02-24 20:02:31 stefan Exp $'
 ! !