From 870174adde8aef34d5c30ead94ea96f5b87855d4 Mon Sep 17 00:00:00 2001
From: Gopi Vishwakarma <gopi.vishwakarma@flipkart.com>
Date: Mon, 28 Jul 2014 03:06:22 +0530
Subject: [PATCH] bug fix in move operation

---
 .../com/github/fge/jsonpatch/diff/DiffFactorizer.java    | 9 ++++++++-
 src/test/resources/jsonpatch/factorizing-diff.json       | 8 ++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/github/fge/jsonpatch/diff/DiffFactorizer.java b/src/main/java/com/github/fge/jsonpatch/diff/DiffFactorizer.java
index 9ca8bfe8..dfb46417 100644
--- a/src/main/java/com/github/fge/jsonpatch/diff/DiffFactorizer.java
+++ b/src/main/java/com/github/fge/jsonpatch/diff/DiffFactorizer.java
@@ -25,6 +25,8 @@
 import com.google.common.base.Equivalence;
 import com.google.common.collect.Lists;
 
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 
@@ -106,6 +108,7 @@ public static void factorizeDiffs(final List<Diff> diffs)
     private static void findPairs(final List<Diff> diffs)
     {
         final int diffsSize = diffs.size();
+        Collection<Diff> alreadyPaired = new HashSet<Diff>();
 
         Diff addition, removal;
 
@@ -119,7 +122,7 @@ private static void findPairs(final List<Diff> diffs)
              */
             for (int removeIndex = 0; removeIndex < diffsSize; removeIndex++) {
                 removal = diffs.get(removeIndex);
-                if (removal.operation != DiffOperation.REMOVE)
+                if (removal.operation != DiffOperation.REMOVE || alreadyPaired.contains(removal))
                     continue;
                 if (!EQUIVALENCE.equivalent(removal.value, addition.value))
                     continue;
@@ -131,6 +134,10 @@ private static void findPairs(final List<Diff> diffs)
                 addition.firstOfPair = addIndex < removeIndex;
                 removal.pairedDiff = addition;
                 removal.firstOfPair = removeIndex < addIndex;
+
+                alreadyPaired.add(removal);
+                alreadyPaired.add(addition);
+
                 break;
             }
         }
diff --git a/src/test/resources/jsonpatch/factorizing-diff.json b/src/test/resources/jsonpatch/factorizing-diff.json
index 98cd3056..2f7ec39a 100644
--- a/src/test/resources/jsonpatch/factorizing-diff.json
+++ b/src/test/resources/jsonpatch/factorizing-diff.json
@@ -296,5 +296,13 @@
             { "op": "remove", "path": "/0" },
             { "op": "remove", "path": "/1" }
         ]
+    },
+    {
+        "first": { "b": [0, 1, 2] },
+        "second": { "b": [1, 2], "c": 0 ,"d":0},
+        "patch": [
+        { "op": "move", "from": "/b/0", "path": "/c"},
+        { "op": "add", "path": "/d", "value": 0}
+        ]
     }
 ]
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