--- a/HierarchicalListView.st	Sun Jul 29 20:37:08 2018 +0200
+++ b/HierarchicalListView.st	Sun Jul 29 20:37:43 2018 +0200
@@ -952,12 +952,14 @@
 
     "/ draw all vertical lines
     "/ take care, list may change while drawing (GUIBrowser when connection goes away!!)
-    list from:start to:(stop min:list size) do:[:eachItem|
-        self drawVericalLineForElement:eachItem minX:xL maxX:xR.
-    ].
-    item notNil ifTrue:[
-        [ (item := item parent) notNil ] whileTrue:[
-            self drawVericalLineForElement:item minX:xL maxX:xR.
+    list synchronized:[
+        list from:start to:(stop min:list size) do:[:eachItem|
+            self drawVericalLineForElement:eachItem minX:xL maxX:xR.
+        ].
+        item notNil ifTrue:[
+            [ (item := item parent) notNil ] whileTrue:[
+                self drawVerticalLineForElement:item minX:xL maxX:xR.
+            ].
         ].
     ].
     
@@ -1010,13 +1012,21 @@
     self mask:nil.
 
     "Modified: / 03-12-2010 / 19:28:23 / cg"
-    "Modified: / 12-06-2018 / 10:46:02 / Claus Gittinger"
     "Modified (comment): / 23-07-2018 / 19:32:06 / Stefan Vogel"
+    "Modified: / 29-07-2018 / 19:12:22 / Claus Gittinger"
 !
 
 drawVericalLineForElement:item minX:xL maxX:xR
     "draw the vertical line my children are connected to"
 
+    self drawVerticalLineForElement:item minX:xL maxX:xR
+
+    "Modified: / 29-07-2018 / 19:11:38 / Claus Gittinger"
+!
+
+drawVerticalLineForElement:item minX:xL maxX:xR
+    "draw the vertical line my children are connected to"
+
     |itemLevel y0 y1 x0|
 
     (item notNil and:[item isExpanded and:[item hasChildren]]) ifTrue:[
@@ -1040,7 +1050,7 @@
         ].
     ].
 
-    "Modified (format): / 04-07-2018 / 08:07:46 / Claus Gittinger"
+    "Created: / 29-07-2018 / 19:11:18 / Claus Gittinger"
 !
 
 validateDrawableIconFor:anItem