Ignore cached files for updates and viewed images if their contents are empty

Core/Utils/TwitterUtils.cs

@@ -83,8 +83,8 @@ namespace TweetDuck.Core.Utils{
             }
 
             string file = Path.Combine(BrowserCache.CacheFolder, GetImageFileName(url) ?? Path.GetRandomFileName());
-
+            
-            if (File.Exists(file)){
+            if (WindowsUtils.FileExistsAndNotEmpty(file)){
                 ViewImageInternal(file);
             }
             else{

Core/Utils/WindowsUtils.cs

@@ -66,6 +66,14 @@ namespace TweetDuck.Core.Utils{
             }
         }
 
+        public static bool FileExistsAndNotEmpty(string path){
+            try{
+                return new FileInfo(path).Length > 0;
+            }catch{
+                return false;
+            }
+        }
+
         public static bool OpenAssociatedProgram(string file, string arguments = "", bool runElevated = false){
             try{
                 using(Process.Start(new ProcessStartInfo{

Updates/UpdateInfo.cs

@@ -26,7 +26,7 @@ namespace TweetDuck.Updates{
         }
 
         public void BeginSilentDownload(){
-            if (File.Exists(InstallerPath)){
+            if (WindowsUtils.FileExistsAndNotEmpty(InstallerPath)){
                 DownloadStatus = UpdateDownloadStatus.Done;
                 return;
             }