Fix Corruped Media Cover Images.

src/NzbDrone.Core/MediaCover/CoverAlreadyExistsSpecification.cs

@@ -1,5 +1,8 @@
-using NzbDrone.Common.Disk;
+using System;
+using NzbDrone.Common.Disk;
 using NzbDrone.Common.Http;
+using System.Drawing;
+using NLog;
 
 namespace NzbDrone.Core.MediaCover
 {
@@ -12,11 +15,13 @@ namespace NzbDrone.Core.MediaCover
     {
         private readonly IDiskProvider _diskProvider;
         private readonly IHttpClient _httpClient;
+        private readonly Logger _logger;
 
-        public CoverAlreadyExistsSpecification(IDiskProvider diskProvider, IHttpClient httpClient)
+        public CoverAlreadyExistsSpecification(IDiskProvider diskProvider, IHttpClient httpClient, Logger logger)
         {
             _diskProvider = diskProvider;
             _httpClient = httpClient;
+            _logger = logger;
         }
 
         public bool AlreadyExists(string url, string path)
@@ -26,9 +31,31 @@ namespace NzbDrone.Core.MediaCover
                 return false;
             }
 
+            if (!IsValidGDIPlusImage(path))
+            {
+                _diskProvider.DeleteFile(path);
+                return false;
+            }
+
             var headers = _httpClient.Head(new HttpRequest(url)).Headers;
             var fileSize = _diskProvider.GetFileSize(path);
             return fileSize == headers.ContentLength;
         }
+
+        private bool IsValidGDIPlusImage(string filename)
+        {
+            try
+            {
+                using (var bmp = new Bitmap(filename))
+                {
+                }
+                return true;
+            }
+            catch (Exception ex)
+            {
+                _logger.Debug(ex, "Corrupted image found at: {0}. Redownloading...", filename);
+                return false;
+            }
+        }
     }
 }