#20644: Working around Azure Websites limitation of not being able to use System.Drawing.Image with .ico files.

WorkItem: 20644

src/Orchard.Web/Modules/Orchard.MediaLibrary/Factories/ImageFactory.cs

@@ -65,12 +65,36 @@ namespace Orchard.MediaLibrary.Factories {
                 return null;
             }
 
+            try {
                 using (var image = Image.FromStream(stream)) {
                     imagePart.Width = image.Width;
                     imagePart.Height = image.Height;
                 }
+            }
+            catch (ArgumentException) {
+                // Still trying to get .ico dimensions when it's blocked in System.Drawing, see: https://orchard.codeplex.com/workitem/20644
+
+                if (mimeType != "image/x-icon" && mimeType != "image/vnd.microsoft.icon") {
+                    throw;
+                }
+
+                TryFillDimensionsForIco(stream, imagePart);
+            }
 
             return part;
         }
+
+        private void TryFillDimensionsForIco(Stream stream, ImagePart imagePart) {
+            stream.Position = 0;
+            using (var binaryReader = new BinaryReader(stream)) {
+                // Reading out the necessary bytes that indicate the image dimensions. For the file format see:
+                // http://en.wikipedia.org/wiki/ICO_%28file_format%29
+                // Reading out leading bytes containing unneded information.
+                binaryReader.ReadBytes(6);
+                // Reading out dimensions. If there are multiple icons bundled in the same file then this is the first image.
+                imagePart.Width = binaryReader.ReadByte();
+                imagePart.Height = binaryReader.ReadByte();
+            }
+        }
     }
 }