Clone provided array

Author: manandre

src/libraries/System.Threading.RateLimiting/src/System/Threading/RateLimiting/ChainedPartitionedRateLimiter.cs

@@ -20,7 +20,7 @@ internal sealed class ChainedPartitionedRateLimiter<TResource> : PartitionedRate
 
         public ChainedPartitionedRateLimiter(PartitionedRateLimiter<TResource>[] limiters)
         {
-            _limiters = limiters;
+            _limiters = (PartitionedRateLimiter<TResource>[])limiters.Clone();
         }
 
         public override RateLimiterStatistics? GetStatistics(TResource resource)

src/libraries/System.Threading.RateLimiting/src/System/Threading/RateLimiting/ChainedRateLimiter.cs

@@ -20,7 +20,7 @@ internal sealed partial class ChainedRateLimiter : RateLimiter
 
         public ChainedRateLimiter(RateLimiter[] limiters)
         {
-            _limiters = limiters;
+            _limiters = (RateLimiter[])limiters.Clone();
         }
 
         public override RateLimiterStatistics? GetStatistics()

src/libraries/System.Threading.RateLimiting/tests/ChainedLimiterTests.cs

@@ -1,10 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 using Xunit;
 
@@ -55,6 +53,20 @@ public async Task DisposeAsyncMakesMethodsThrow()
             await Assert.ThrowsAsync<ObjectDisposedException>(async () => await chainedLimiter.AcquireAsync());
         }
 
+        [Fact]
+        public void ArrayChangesAreIgnored()
+        {
+            using var limiter1 = new CustomizableLimiter { IdleDurationImpl = () => TimeSpan.FromMilliseconds(1) };
+            using var limiter2 = new CustomizableLimiter { IdleDurationImpl = () => TimeSpan.FromMilliseconds(2) };
+            var limiters = new RateLimiter[] { limiter1 };
+            var chainedLimiter = RateLimiter.CreateChained(limiters);
+
+            limiters[0] = limiter2;
+
+            var idleDuration = chainedLimiter.IdleDuration;
+            Assert.Equal(1, idleDuration.Value.TotalMilliseconds);
+        }
+
         [Fact]
         public void GetStatisticsReturnsLowestOrAggregateValues()
         {

src/libraries/System.Threading.RateLimiting/tests/PartitionedChainedLimiterTests.cs

@@ -1,10 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 using Xunit;
 
@@ -89,6 +87,25 @@ public async Task DisposeAsyncMakesMethodsThrow()
             await Assert.ThrowsAsync<ObjectDisposedException>(async () => await chainedLimiter.AcquireAsync(""));
         }
 
+        [Fact]
+        public void ArrayChangesAreIgnored()
+        {
+            using var limiter1 = PartitionedRateLimiter.Create<string, int>(resource =>
+            {
+                return RateLimitPartition.Get(1, key => new NotImplementedLimiter());
+            });
+            using var limiter2 = PartitionedRateLimiter.Create<string, int>(resource =>
+            {
+                return RateLimitPartition.Get(1, key => new CustomizableLimiter());
+            });
+            var limiters = new PartitionedRateLimiter<string>[] { limiter1 };
+            var chainedLimiter = PartitionedRateLimiter.CreateChained(limiters);
+
+            limiters[0] = limiter2;
+
+            Assert.Throws<NotImplementedException>(() => chainedLimiter.AttemptAcquire(""));
+        }
+
         [Fact]
         public void GetStatisticsReturnsLowestOrAggregateValues()
         {