Fix SourceCacheContext initialization

src/NuGet.CatalogReader/Common/TaskUtils.cs

@@ -39,7 +39,7 @@ public static Task RunAsync(IEnumerable<Func<Task>> tasks, bool useTaskRun, Canc
         {
             return RunAsync(
                 tasks: tasks.Select(GetFuncWithReturnValue),
-                useTaskRun: false,
+                useTaskRun: useTaskRun,
                 token: token);
         }
 
@@ -50,7 +50,7 @@ public static Task RunAsync(IEnumerable<Func<Task>> tasks, bool useTaskRun, int
         {
             return RunAsync(
                 tasks: tasks.Select(GetFuncWithReturnValue),
-                useTaskRun: false,
+                useTaskRun: useTaskRun,
                 maxThreads: maxThreads,
                 token: token);
         }

src/NuGet.CatalogReader/HttpReaderBase.cs

@@ -79,7 +79,7 @@ public HttpReaderBase(Uri indexUri, TimeSpan cacheTimeout, ILogger log)
         /// <param name="messageHandler">HTTP message handler.</param>
         public HttpReaderBase(Uri indexUri, HttpMessageHandler messageHandler)
             : this(indexUri,
-                  messageHandler: null,
+                  messageHandler: messageHandler,
                   log: null)
         {
         }
@@ -108,22 +108,26 @@ public HttpReaderBase(Uri indexUri, HttpSource httpSource, SourceCacheContext ca
         {
             _indexUri = indexUri ?? throw new ArgumentNullException(nameof(indexUri));
             _log = log ?? NullLogger.Instance;
-            _sourceCacheContext = cacheContext ?? new SourceCacheContext();
-
             _httpSource = httpSource;
 
-            // TODO: what should retry be?
-            _cacheContext = HttpSourceCacheContext.Create(_sourceCacheContext, 5);
-
-            if (_sourceCacheContext == null)
+            // Initialize the cache context used by HttpSource. If a SourceCacheContext
+            // was not provided, create one and respect the cache timeout parameter.
+            if (cacheContext == null)
             {
                 var sourceCacheContext = new SourceCacheContext()
                 {
                     MaxAge = DateTimeOffset.UtcNow.Subtract(cacheTimeout),
                 };
 
-                _cacheContext = HttpSourceCacheContext.Create(sourceCacheContext, 5);
+                _sourceCacheContext = sourceCacheContext;
             }
+            else
+            {
+                _sourceCacheContext = cacheContext;
+            }
+
+            // TODO: what should retry be?
+            _cacheContext = HttpSourceCacheContext.Create(_sourceCacheContext, 5);
         }
 
         /// <summary>

src/NuGet.CatalogReader/ProcessEntriesUtility.cs

@@ -29,7 +29,7 @@ public static Task<IReadOnlyList<FileInfo>> DownloadNupkgsAsync(string outputDir
         {
             var entriesArray = entries.ToArray();
 
-            if (entries.Distinct().Count() != entriesArray.Length)
+            if (entriesArray.Distinct().Count() != entriesArray.Length)
             {
                 throw new InvalidOperationException("Duplicate entries detected. Entries must be unique by id/version.");
             }
@@ -63,7 +63,7 @@ public static async Task<IReadOnlyList<T>> RunAsync<T>(Func<CatalogEntry, Task<T
         {
             var entriesArray = entries.ToArray();
 
-            maxThreads = Math.Min(1, maxThreads);
+            maxThreads = Math.Max(1, maxThreads);
 
             var files = new List<T>(entriesArray.Length);
             var tasks = new List<Task<T>>(maxThreads);

src/NuGetMirror/Common/TaskUtils.cs

@@ -39,7 +39,7 @@ public static Task RunAsync(IEnumerable<Func<Task>> tasks, bool useTaskRun, Canc
         {
             return RunAsync(
                 tasks: tasks.Select(GetFuncWithReturnValue),
-                useTaskRun: false,
+                useTaskRun: useTaskRun,
                 token: token);
         }
 
@@ -50,7 +50,7 @@ public static Task RunAsync(IEnumerable<Func<Task>> tasks, bool useTaskRun, int
         {
             return RunAsync(
                 tasks: tasks.Select(GetFuncWithReturnValue),
-                useTaskRun: false,
+                useTaskRun: useTaskRun,
                 maxThreads: maxThreads,
                 token: token);
         }