Index: FolderOrder.java
===================================================================
RCS file: /cvs/openide/src/org/openide/loaders/FolderOrder.java,v
retrieving revision 1.6
diff -u -t -r1.6 FolderOrder.java
--- FolderOrder.java	27 Sep 2001 14:01:11 -0000	1.6
+++ FolderOrder.java	5 Oct 2001 17:44:20 -0000
@@ -37,10 +37,19 @@
     /** a static map with (FileObject, Reference (Folder))
      */
     private static final WeakHashMap map = new WeakHashMap (101);
+    /** A static of known folder orders. Though we hold the
+     * FolderOrder with a soft reference which can be collected, even
+     * if this happens we would like the new FolderOrder to have any
+     * previously determined order attribute. Otherwise under obscure
+     * circumstances (#15381) it is possible for the IDE to go into an
+     * endless loop recalculating folder orders, since they keep
+     * getting collected.
+     */
+    private static final Map knownOrders = Collections.synchronizedMap(new WeakHashMap(50)); // Map<FileObject, Object>
     
 
-    /** map of primary files of objects to their index or null */
-    private Map order; // Map<FileObject,Integer>
+    /** map of names of primary files of objects to their index or null */
+    private Map order; // Map<String,Integer>
     /** file to store data in */
     private FileObject folder;
     /** if true, partial orderings on disk should be ignored for files in the order */
@@ -269,6 +278,9 @@
         doRead (o);
         
         previous = o;
+        if (previous != null) {
+            knownOrders.put(folder, previous);
+        }
         
         FolderList.changedFolderOrder (folder);
     }
@@ -384,6 +396,8 @@
         FolderOrder order = ref == null ? null : (FolderOrder)ref.get ();
         if (order == null) {
             order = new FolderOrder (folder);
+            order.previous = knownOrders.get(folder);
+            order.doRead(order.previous);
             
             map.put (folder, new SoftReference (order));
         }