From 7aead04482f7d80613ad1e8e7a28eb4fe9e7467a Mon Sep 17 00:00:00 2001
From: Julien Ignace <julien@unity3d.com>
Date: Fri, 24 Sep 2021 16:02:47 +0200
Subject: [PATCH] Fixed an issue with AddRange not keeping previous content
 when out of space.

---
 .../Runtime/Common/DynamicArray.cs            |  2 +-
 .../Tests/Editor/DynamicArrayTests.cs         | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/com.unity.render-pipelines.core/Runtime/Common/DynamicArray.cs b/com.unity.render-pipelines.core/Runtime/Common/DynamicArray.cs
index 2e61659d3b0..f27a883a9be 100644
--- a/com.unity.render-pipelines.core/Runtime/Common/DynamicArray.cs
+++ b/com.unity.render-pipelines.core/Runtime/Common/DynamicArray.cs
@@ -87,7 +87,7 @@ public int Add(in T value)
         /// <param name="array">The array whose elements should be added to the end of the DynamicArray. The array itself cannot be null, but it can contain elements that are null, if type T is a reference type.</param>
         public void AddRange(DynamicArray<T> array)
         {
-            Reserve(size + array.size);
+            Reserve(size + array.size, true);
             for (int i = 0; i < array.size; ++i)
                 m_Array[size++] = array[i];
         }
diff --git a/com.unity.render-pipelines.core/Tests/Editor/DynamicArrayTests.cs b/com.unity.render-pipelines.core/Tests/Editor/DynamicArrayTests.cs
index 8926775936d..1f6c78dcd74 100644
--- a/com.unity.render-pipelines.core/Tests/Editor/DynamicArrayTests.cs
+++ b/com.unity.render-pipelines.core/Tests/Editor/DynamicArrayTests.cs
@@ -58,6 +58,26 @@ public void TestAddRangeCorrectElements()
             Assert.AreEqual(4, m_DynamicArray.size);
         }
 
+        [Test]
+        public void TestAddRangeOutOfSpaceKeepPreviousElements()
+        {
+            var smallDynamicArray = new DynamicArray<int>(2);
+            smallDynamicArray[0] = 1;
+            smallDynamicArray[1] = 2;
+
+            var otherArray = new DynamicArray<int>();
+            otherArray.Add(3);
+            otherArray.Add(4);
+
+            smallDynamicArray.AddRange(otherArray);
+
+            Assert.AreEqual(1, smallDynamicArray[0]);
+            Assert.AreEqual(2, smallDynamicArray[1]);
+            Assert.AreEqual(3, smallDynamicArray[2]);
+            Assert.AreEqual(4, smallDynamicArray[3]);
+            Assert.AreEqual(4, smallDynamicArray.size);
+        }
+
         [Test]
         public void TestRemoveElementCorrectSize()
         {