Index: oak-store-document/src/main/java/org/apache/jackrabbit/oak/plugins/document/DocumentNodeStoreBranch.java
===================================================================
--- oak-store-document/src/main/java/org/apache/jackrabbit/oak/plugins/document/DocumentNodeStoreBranch.java	(revision 1875917)
+++ oak-store-document/src/main/java/org/apache/jackrabbit/oak/plugins/document/DocumentNodeStoreBranch.java	(working copy)
@@ -40,6 +40,7 @@
 import org.apache.jackrabbit.oak.plugins.memory.MemoryNodeBuilder;
 import org.apache.jackrabbit.oak.spi.commit.CommitHook;
 import org.apache.jackrabbit.oak.spi.commit.CommitInfo;
+import org.apache.jackrabbit.oak.spi.state.ApplyDiff;
 import org.apache.jackrabbit.oak.spi.state.ConflictAnnotatingRebaseDiff;
 import org.apache.jackrabbit.oak.spi.state.NodeBuilder;
 import org.apache.jackrabbit.oak.spi.state.NodeState;
@@ -496,9 +497,13 @@
                 branchState = new Unmodified(base);
             } else {
                 int numChanges = countChanges(base, root);
-                head = newModifiedDocumentNodeState(root);
                 if (numChanges > updateLimit) {
+                    head = newModifiedDocumentNodeState(root);
                     persist();
+                } else {
+                    NodeBuilder builder = new MemoryNodeBuilder(base);
+                    root.compareAgainstBaseState(base, new ApplyDiff(builder));
+                    head = newModifiedDocumentNodeState(builder.getNodeState());
                 }
             }
         }
Index: oak-store-document/src/test/java/org/apache/jackrabbit/oak/plugins/document/DocumentNodeStoreBranchTest.java
===================================================================
--- oak-store-document/src/test/java/org/apache/jackrabbit/oak/plugins/document/DocumentNodeStoreBranchTest.java	(revision 1875917)
+++ oak-store-document/src/test/java/org/apache/jackrabbit/oak/plugins/document/DocumentNodeStoreBranchTest.java	(working copy)
@@ -16,7 +16,9 @@
  */
 package org.apache.jackrabbit.oak.plugins.document;
 
+import org.apache.jackrabbit.oak.json.JsopDiff;
 import org.apache.jackrabbit.oak.spi.state.NodeBuilder;
+import org.apache.jackrabbit.oak.spi.state.NodeState;
 import org.junit.Rule;
 import org.junit.Test;
 
@@ -103,4 +105,21 @@
             // expected
         }
     }
+    
+    @Test
+    public void noopChanges() throws Exception {
+    	// Run this test with JVM argument: -Xss256k
+    	// It should not produce a StackOverflow exception
+        DocumentNodeStore ns = builderProvider.newBuilder().setUpdateLimit(10).getNodeStore();
+        NodeBuilder builder = ns.getRoot().builder();
+        builder.child("a").setProperty("p", 1);
+        merge(ns, builder);
+        NodeState root = ns.getRoot();
+        builder = root.builder();
+        builder.child("b");
+        for (int i = 0; i < ns.getUpdateLimit() * 2000; i++) {
+            builder.child("a").setProperty("p", 1);
+        }
+        builder.getNodeState().compareAgainstBaseState(root, new JsopDiff());
+    }
 }