From 8245e65d3ffdc45772b5c776856bc1a3a05bd604 Mon Sep 17 00:00:00 2001
From: webzwo0i <webzwo0i@c3d2.de>
Date: Thu, 20 Feb 2014 18:13:30 +0100
Subject: [PATCH] disconnect client if it submits an already accepted changeset
 based on an old revision

---
 src/node/handler/PadMessageHandler.js | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/node/handler/PadMessageHandler.js b/src/node/handler/PadMessageHandler.js
index 774ebf081..05705e010 100644
--- a/src/node/handler/PadMessageHandler.js
+++ b/src/node/handler/PadMessageHandler.js
@@ -682,6 +682,14 @@ function handleUserChanges(data, cb)
             // and can be applied after "c".
             try
             {
+              // a changeset can be based on an old revision with the same changes in it
+              // prevent eplite from accepting it TODO: better send the client a NEW_CHANGES
+              // of that revision
+              if(baseRev+1 == r && c == changeset) {
+                client.json.send({disconnect:"badChangeset"});
+                stats.meter('failedChangesets').mark();
+                return callback(new Error("Won't apply USER_CHANGES, because it contains an already accepted changeset"));
+              }
               changeset = Changeset.follow(c, changeset, false, apool);
             }catch(e){
               client.json.send({disconnect:"badChangeset"});