--- a/ProjectDefinition.st	Thu Apr 04 13:50:52 2013 +0200
+++ b/ProjectDefinition.st	Thu Apr 04 14:19:49 2013 +0200
@@ -875,6 +875,33 @@
     "Created: / 30-08-2007 / 18:28:28 / cg"
 !
 
+excludeMethodFor:selector inClassNamed:className usingCompiler:compilerOrNil
+    "exclude (remove from extensionList) a method by name.
+     Because this requires compilation of my extensionMethodNames-method, a compiler can be passed in,
+     which has to do the job.
+     This is used by the systembrowser to pass in a CodeGeneratorTool with undo support.
+     If nil is passed in, the recurlar compiler is used (no undo support)"
+
+    |oldSpec newSpec newCode extensionMethods idx|
+
+    oldSpec := self extensionMethodNames.
+    newSpec := oldSpec copy.
+    extensionMethods := self extensionMethods.
+
+    idx := (1 to:newSpec size-1 by:2) 
+                detect:[:i |
+                    ((newSpec at:i) = className)
+                    and:[ (newSpec at:i+1) = selector ]]
+                ifNone:nil.
+    idx isNil ifTrue:[ ^ self ].
+
+    "/ attention: there are two spec-elements per method
+    newSpec := newSpec removeFromIndex:idx toIndex:idx+1.
+
+    newCode := self extensionMethodNames_code_For:newSpec.
+    self compile:newCode categorized:'description - contents' using:compilerOrNil
+!
+
 excludeMethods:toRemove usingCompiler:compilerOrNil
     "exclude (remove from extensionList) a number of methods.
      Because this requires compilation of my extensionMethodNames-method, a compiler can be passed in,
@@ -894,11 +921,15 @@
         (extensionMethods includes:eachMethodToRemove) ifTrue:[
             className := eachMethodToRemove mclass name.
             selector := eachMethodToRemove selector.
-            idx := (1 to:newSpec size-1 by:2) detect:[:i |
-                ((newSpec at:i) = className)
-                and:[ (newSpec at:i+1) = selector ]].
-
-            newSpec := newSpec removeFromIndex:idx toIndex:idx+1
+            idx := (1 to:newSpec size-1 by:2) 
+                        detect:[:i |
+                            ((newSpec at:i) = className)
+                            and:[ (newSpec at:i+1) = selector ]]
+                        ifNone:nil.
+            idx notNil ifTrue:[
+                "/ attention: there are two spec-elements per method
+                newSpec := newSpec removeFromIndex:idx toIndex:idx+1
+            ]
         ].
     ].
 
@@ -7356,11 +7387,11 @@
 !ProjectDefinition class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/ProjectDefinition.st,v 1.453 2013-04-04 11:48:58 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/ProjectDefinition.st,v 1.454 2013-04-04 12:19:49 cg Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic/ProjectDefinition.st,v 1.453 2013-04-04 11:48:58 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/ProjectDefinition.st,v 1.454 2013-04-04 12:19:49 cg Exp $'
 !
 
 version_SVN