From 574fc7635e75cc08306baaf4ddce8cb72177e4fe Mon Sep 17 00:00:00 2001
From: Manodasan Wignarajah <mawign@microsoft.com>
Date: Tue, 5 Apr 2022 16:41:06 -0700
Subject: [PATCH] Fix boxing empty blittable arrays (#1158)

* Fix boxing blittable empty arrays

* Update testwinrt repo
---
 .../UnitTest/TestComponentCSharp_Tests.cs     | 22 ++++++
 src/Tests/UnitTest/TestComponent_Tests.cs     | 68 +++++++++++++++++++
 src/WinRT.Runtime/Marshalers.cs               |  9 +++
 src/get_testwinrt.cmd                         |  2 +-
 4 files changed, 100 insertions(+), 1 deletion(-)

diff --git a/src/Tests/UnitTest/TestComponentCSharp_Tests.cs b/src/Tests/UnitTest/TestComponentCSharp_Tests.cs
index e2ade8cdd..266c00e19 100644
--- a/src/Tests/UnitTest/TestComponentCSharp_Tests.cs
+++ b/src/Tests/UnitTest/TestComponentCSharp_Tests.cs
@@ -887,6 +887,28 @@ public void TestValueSet()
             {
                 Assert.Equal(valueSet[item.Key], item.Value);
             }
+        }
+
+        [Fact]
+        public void TestValueSetArrays()
+        {
+            var map = new Dictionary<string, long[]>
+            { 
+                ["foo"] = new long[] { 1, 2, 3 },
+                ["hello"] = new long[0], 
+                ["world"] = new long[] { 1, 2, 3 }, 
+                ["bar"] = new long[0]
+            };
+            var valueSet = new Windows.Foundation.Collections.ValueSet();
+            foreach (var item in map)
+            {
+                valueSet[item.Key] = item.Value;
+            }
+            Assert.Equal(map.Count, valueSet.Count);
+            foreach (var item in map)
+            {
+                Assert.Equal(valueSet[item.Key], item.Value);
+            }
         }
 
         [Fact]
diff --git a/src/Tests/UnitTest/TestComponent_Tests.cs b/src/Tests/UnitTest/TestComponent_Tests.cs
index a493a3fc7..afc2d29f1 100644
--- a/src/Tests/UnitTest/TestComponent_Tests.cs
+++ b/src/Tests/UnitTest/TestComponent_Tests.cs
@@ -1085,6 +1085,74 @@ public void Box_DateTime()
             Box_type(DateTimeOffset.Now, Tests.Box17);
         }
 
+        [Fact]
+        public void Box_LongArray()
+        {
+            long[] arr = new long[] { 2, 4, 6 };
+            Box_type(arr, Tests.Box18);
+
+            long[] arr2 = new long[] { 2, 4, 6 };
+            Box_type(arr2, Tests.Box18);
+            Box_type(arr2, Tests.Box18);
+
+            long[] arr3 = new long[0];
+            Box_type(arr3, Tests.Box18);
+
+            long[] arr4 = new long[0];
+            Box_type(arr4, Tests.Box18);
+        }
+
+        [Fact]
+        public void Box_BoolArray()
+        {
+            bool[] arr = new bool[] { true, false, true };
+            Box_type(arr, Tests.Box19);
+
+            bool[] arr2 = new bool[] { true, false, true };
+            Box_type(arr2, Tests.Box19);
+            Box_type(arr2, Tests.Box19);
+
+            bool[] arr3 = new bool[0];
+            Box_type(arr3, Tests.Box19);
+
+            bool[] arr4 = new bool[0];
+            Box_type(arr4, Tests.Box19);
+        }
+
+        [Fact]
+        public void Box_StringArray()
+        {
+            string[] arr = new string[] { "one", "two", "three" };
+            Box_type(arr, Tests.Box20);
+
+            string[] arr2 = new string[] { "four", "five", "six" };
+            Box_type(arr2, Tests.Box20);
+            Box_type(arr2, Tests.Box20);
+
+            string[] arr3 = new string[0];
+            Box_type(arr3, Tests.Box20);
+
+            string[] arr4 = new string[0];
+            Box_type(arr4, Tests.Box20);
+        }
+
+        [Fact]
+        public void Box_TimeSpanArray()
+        {
+            TimeSpan[] arr = new TimeSpan[] { TimeSpan.FromMilliseconds(4), TimeSpan.FromMilliseconds(5), TimeSpan.FromMilliseconds(6) };
+            Box_type(arr, Tests.Box21);
+
+            TimeSpan[] arr2 = new TimeSpan[] { TimeSpan.FromMilliseconds(4), TimeSpan.FromMilliseconds(5), TimeSpan.FromMilliseconds(6) };
+            Box_type(arr2, Tests.Box21);
+            Box_type(arr2, Tests.Box21);
+
+            TimeSpan[] arr3 = new TimeSpan[0];
+            Box_type(arr3, Tests.Box21);
+
+            TimeSpan[] arr4 = new TimeSpan[0];
+            Box_type(arr4, Tests.Box21);
+        }
+
         [Fact]
         public void Fast_Abi_Simple()
         {
diff --git a/src/WinRT.Runtime/Marshalers.cs b/src/WinRT.Runtime/Marshalers.cs
index 8abafa290..dcb61f881 100644
--- a/src/WinRT.Runtime/Marshalers.cs
+++ b/src/WinRT.Runtime/Marshalers.cs
@@ -386,6 +386,15 @@ public static unsafe T[] FromAbiArray(object box)
             {
                 return null;
             }
+
+            // For empty arrays, we can end up returning the same managed object
+            // when using ReadOnlySpan.ToArray. But a unique object is expected
+            // by the caller for RCW creation.
+            if (abi.length == 0)
+            {
+                return new T[0];
+            }
+
             var abiSpan = new ReadOnlySpan<T>(abi.data.ToPointer(), abi.length);
             return abiSpan.ToArray();
         }
diff --git a/src/get_testwinrt.cmd b/src/get_testwinrt.cmd
index 222ef31e9..85b4a3586 100644
--- a/src/get_testwinrt.cmd
+++ b/src/get_testwinrt.cmd
@@ -14,7 +14,7 @@ git checkout -f master
 if ErrorLevel 1 popd & exit /b !ErrorLevel!
 git fetch -f
 if ErrorLevel 1 popd & exit /b !ErrorLevel!
-git reset -q --hard 53e87ecb7dd2fc883062ea9d95296768b604f058
+git reset -q --hard d7acaf7d18d7902f7181ee094a27966b2b5b87f0
 if ErrorLevel 1 popd & exit /b !ErrorLevel!
 echo Restoring Nuget
 %this_dir%.nuget\nuget.exe restore