Index: openide/src/org/openide/util/Lookup.java
===================================================================
RCS file: /cvs/openide/src/org/openide/util/Lookup.java,v
retrieving revision 1.23
diff -u -r1.23 Lookup.java
--- openide/src/org/openide/util/Lookup.java	14 Jul 2003 06:04:13 -0000	1.23
+++ openide/src/org/openide/util/Lookup.java	16 Jul 2003 14:38:48 -0000
@@ -295,7 +295,7 @@
          * @since 1.8
          */
         public java.util.Collection allItems () {
-            return java.util.Collections.EMPTY_LIST;
+            return java.util.Collections.EMPTY_SET;
         }
     }
     
@@ -382,7 +382,7 @@
              * @return collection of all instances
              */
             public java.util.Collection allInstances () {
-                return java.util.Collections.EMPTY_LIST;
+                return java.util.Collections.EMPTY_SET;
             }
         };
         
Index: openide/src/org/openide/util/lookup/SimpleProxyLookup.java
===================================================================
RCS file: /cvs/openide/src/org/openide/util/lookup/SimpleProxyLookup.java,v
retrieving revision 1.3
diff -u -r1.3 SimpleProxyLookup.java
--- openide/src/org/openide/util/lookup/SimpleProxyLookup.java	16 Oct 2002 13:02:44 -0000	1.3
+++ openide/src/org/openide/util/lookup/SimpleProxyLookup.java	16 Jul 2003 14:38:48 -0000
@@ -137,6 +137,18 @@
             
             Collection newPairs = delegate.allItems ();
             
+            // See #34961 for explanation.
+            if (!(oldPairs instanceof List)) {
+                if (oldPairs == Collections.EMPTY_SET) {
+                    // avoid allocation
+                    oldPairs = Collections.EMPTY_LIST;
+                } else {
+                    oldPairs = new ArrayList(oldPairs);
+                }
+            }
+            if (!(newPairs instanceof List)) {
+                newPairs = new ArrayList(newPairs);
+            }
             return !oldPairs.equals (newPairs);
         }