From 3340933a01945fb517775a0e0f079a701d04f094 Mon Sep 17 00:00:00 2001
From: Manish R Jain <manish@dgraph.io>
Date: Wed, 13 Jun 2018 16:21:36 -0700
Subject: [PATCH] Bug fixes related to txn nil callbacks and badgerMove key.

---
 iterator.go    | 4 +++-
 transaction.go | 2 +-
 value.go       | 3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/iterator.go b/iterator.go
index 51a0a242b..7fa1068fe 100644
--- a/iterator.go
+++ b/iterator.go
@@ -167,7 +167,9 @@ func (item *Item) yieldItemValue() ([]byte, func(), error) {
 		// The value pointer is pointing to a deleted value log. Look for the
 		// move key and read that instead.
 		runCallback(cb)
-		key = append(badgerMove, y.KeyWithTs(item.Key(), item.Version())...)
+		// Do not put badgerMove on the left in append. It seems to cause some sort of manipulation.
+		key = append([]byte{}, badgerMove...)
+		key = append(key, y.KeyWithTs(item.Key(), item.Version())...)
 		// Note that we can't set item.key to move key, because that would
 		// change the key user sees before and after this call. Also, this move
 		// logic is internal logic and should not impact the external behavior
diff --git a/transaction.go b/transaction.go
index de5f479c8..b56d3b9ff 100644
--- a/transaction.go
+++ b/transaction.go
@@ -411,7 +411,7 @@ func (txn *Txn) runCallbacks() {
 	for _, cb := range txn.callbacks {
 		cb()
 	}
-	txn.callbacks = nil
+	txn.callbacks = txn.callbacks[:0]
 }
 
 // Discard discards a created transaction. This method is very important and must be called. Commit
diff --git a/value.go b/value.go
index cad584a6b..d6b9e5635 100644
--- a/value.go
+++ b/value.go
@@ -387,7 +387,8 @@ func (vlog *valueLog) rewrite(f *logFile, tr trace.Trace) error {
 			if bytes.HasPrefix(e.Key, badgerMove) {
 				ne.Key = append([]byte{}, e.Key...)
 			} else {
-				ne.Key = append(badgerMove, e.Key...)
+				ne.Key = append([]byte{}, badgerMove...)
+				ne.Key = append(ne.Key, e.Key...)
 			}
 
 			ne.Value = append([]byte{}, e.Value...)