dotnet · mstfbl · Mar 25, 2020 · Mar 13, 2020 · Mar 16, 2020 · Mar 16, 2020
diff --git a/src/Microsoft.ML.Core/Utilities/ResourceManagerUtils.cs b/src/Microsoft.ML.Core/Utilities/ResourceManagerUtils.cs
@@ -121,12 +121,12 @@ private async Task<string> DownloadFromUrlWithRetryAsync(IHostEnvironment env, I
             for (int i = 0; i < retryTimes; ++i)
             {
                 var thisDownloadResult = await DownloadFromUrlAsync(env, ch, url, fileName, timeout, filePath);
-
                 if (string.IsNullOrEmpty(thisDownloadResult))
                     return thisDownloadResult;
                 else
+                {
                     downloadResult += thisDownloadResult + @"\n";
-
+                }
                 await Task.Delay(10 * 1000);
             }
 
@@ -160,27 +160,8 @@ private async Task<string> DownloadFromUrlAsync(IHostEnvironment env, IChannel c
                     deleteNeeded = true;
                     return (await t).Message;
                 }
-
-                return CheckValidDownload(ch, filePath, url, ref deleteNeeded);
-            }
-        }
-
-        private static string CheckValidDownload(IChannel ch, string filePath, string url, ref bool deleteNeeded)
-        {
-            // If the relative url does not exist, aka.ms redirects to www.microsoft.com. Make sure this did not happen.
-            // If the file is big then it is definitely not the redirect.
-            var info = new FileInfo(filePath);
-            if (info.Length > 4096)
                 return null;
-            string error = null;
-            using (var r = new StreamReader(filePath))
-            {
-                var text = r.ReadToEnd();
-                if (text.Contains("<head>") && text.Contains("<body>") && text.Contains("microsoft.com"))
-                    error = $"The url '{url}' does not exist. Url was redirected to www.microsoft.com.";
             }
-            deleteNeeded = error != null;
-            return error;
         }
 
         private static void TryDelete(IChannel ch, string filePath, bool warn = true)
@@ -274,6 +255,8 @@ private Exception DownloadResource(IHostEnvironment env, IChannel ch, WebClient
                 using (var ws = fh.CreateWriteStream())
                 {
                     var headers = webClient.ResponseHeaders.GetValues("Content-Length");
+                    if (IsRedirectToDefaultPage(uri.AbsoluteUri))
+                        return ch.Except($"The provided url ({uri}) redirects to the default url ({DefaultUrl})");
                     if (Utils.Size(headers) == 0 || !long.TryParse(headers[0], out var size))
                         size = 10000000;
 
@@ -311,6 +294,36 @@ private Exception DownloadResource(IHostEnvironment env, IChannel ch, WebClient
             }
         }
 
+        /// <summary>This method checks whether or not the provided url redirects to
+        /// the default url <see cref="ResourceManagerUtils.DefaultUrl"/>.</summary>
+        /// <param name="url"> The provided url to check </param>
+        public bool IsRedirectToDefaultPage(string url)
+        {
+            try
+            {
+                var request = WebRequest.Create(url);
+                // FileWebRequests cannot be redirected to default aka.ms webpage <see cref="Default"/>
+                if (request.GetType() == typeof(FileWebRequest))
+                    return false;
+                HttpWebRequest httpWebRequest = (HttpWebRequest)request;
+                httpWebRequest.AllowAutoRedirect = false;
+                HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();
+            }
+            catch (WebException e)
+            {
+                HttpStatusCode statusCode = ((HttpWebResponse)e.Response).StatusCode;
+                // Redirects to default url
+                if (statusCode == HttpStatusCode.Redirect)
+                    return true;
+                // Redirects to another url
+                else if (statusCode == HttpStatusCode.MovedPermanently)
+                    return false;
+                else
+                    return false;
+            }
+            return false;
+        }
+
         public static ResourceDownloadResults GetErrorMessage(out string errorMessage, params ResourceDownloadResults[] result)
         {
             var errorResult = result.FirstOrDefault(res => !string.IsNullOrEmpty(res.ErrorMessage));
@@ -328,4 +341,15 @@ public static ResourceDownloadResults GetErrorMessage(out string errorMessage, p
         private static extern int chmod(string pathname, int mode);
 #pragma warning restore IDE1006
     }
+
+    public class WebClientResponse : WebClient
+    {
+        public WebResponse Response { get; private set; }
+
+        protected override WebResponse GetWebResponse(WebRequest request)
+        {
+            Response = base.GetWebResponse(request);
+            return Response;
+        }
+    }
 }
diff --git a/src/Microsoft.ML.Transforms/Text/WordEmbeddingsExtractor.cs b/src/Microsoft.ML.Transforms/Text/WordEmbeddingsExtractor.cs
@@ -628,7 +628,7 @@ private string EnsureModelFile(IHostEnvironment env, out int linesToSkip, WordEm
                 {
                     string dir = kind == WordEmbeddingEstimator.PretrainedModelKind.SentimentSpecificWordEmbedding ? Path.Combine("Text", "Sswe") : "WordVectors";
                     var url = $"{dir}/{modelFileName}";
-                    var ensureModel = ResourceManagerUtils.Instance.EnsureResourceAsync(Host, ch, url, modelFileName, dir, Timeout);
+                    var ensureModel = ResourceManagerUtils.Instance.EnsureResourceAsync(env, ch, url, modelFileName, dir, Timeout);
                     ensureModel.Wait();
                     var errorResult = ResourceManagerUtils.GetErrorMessage(out var errorMessage, ensureModel.Result);
                     if (errorResult != null)