Index: lucene/CHANGES.txt
===================================================================
--- lucene/CHANGES.txt	(revision 1062641)
+++ lucene/CHANGES.txt	(working copy)
@@ -362,6 +362,9 @@
   internally, it now calls Similarity.idfExplain(Collection, IndexSearcher).
   (Robert Muir)
 
+* LUCENE-2693: RAM used by IndexWriter was slightly incorrectly computed. 
+  (Jason Rutherglen via Shai Erera)
+
 New features
 
 * LUCENE-2128: Parallelized fetching document frequencies during weight
Index: lucene/src/java/org/apache/lucene/index/SegmentDeletes.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentDeletes.java	(revision 1062641)
+++ lucene/src/java/org/apache/lucene/index/SegmentDeletes.java	(working copy)
@@ -140,8 +140,11 @@
   }
 
   public void addQuery(Query query, int docIDUpto) {
-    queries.put(query, docIDUpto);
-    bytesUsed.addAndGet(BYTES_PER_DEL_QUERY);
+    Integer current = queries.put(query, docIDUpto);
+    // increment bytes used only if the query wasn't add so far.
+    if (current == null) {
+      bytesUsed.addAndGet(BYTES_PER_DEL_QUERY);
+    }
   }
 
   public void addDocID(int docID) {