Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/observation/ChangeDispatcher.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/observation/ChangeDispatcher.java	(date 1371657236000)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/observation/ChangeDispatcher.java	(revision )
@@ -197,7 +197,7 @@
                     add(changeSet);
                 }
             }
-            return changeSets.isEmpty() ? null : changeSets.remove();
+            return ChangeSet.aggregate(changeSets);
         }
 
         private void add(ChangeSet changeSet) {
@@ -217,12 +217,40 @@
         private final NodeState before;
         private final NodeState after;
 
+        @Nonnull
         static ChangeSet local(NodeState base, NodeState head, ContentSession contentSession) {
             return new InternalChangeSet(base, head, contentSession, System.currentTimeMillis());
         }
 
+        @Nonnull
         static ChangeSet external(NodeState base, NodeState head) {
             return new ExternalChangeSet(base, head);
+        }
+
+        @CheckForNull
+        static ChangeSet aggregate(Queue<ChangeSet> changeSets) {
+            ChangeSet first = changeSets.peek();
+            ChangeSet last = first;
+            ChangeSet next = first;
+            while (next != null && canAggregate(first, next)) {
+                last = changeSets.remove();
+                next = changeSets.peek();
+            }
+
+            if (first == last) {
+                return first;
+            }
+
+            InternalChangeSet f = (InternalChangeSet) first;
+            InternalChangeSet l = (InternalChangeSet) last;
+            return new InternalChangeSet(first.before, last.after, l.contentSession, last.getDate());  // michid date is broken
+        }
+
+        private static boolean canAggregate(ChangeSet first, ChangeSet last) {
+            InternalChangeSet f = (InternalChangeSet) first;
+            InternalChangeSet l = (InternalChangeSet) last;
+
+            return !f.isExternal() && !l.isExternal() && f.contentSession == l.contentSession;
         }
 
         protected ChangeSet(NodeState before, NodeState after) {