(OpenImage): dispose input on exception.

GameRes/ArchiveFormat.cs

@@ -67,8 +67,16 @@ namespace GameRes
         public virtual IImageDecoder OpenImage (ArcFile arc, Entry entry)
         {
             var input = arc.OpenBinaryEntry (entry);
+            try
+            {
                 return new ImageFormatDecoder (input);
             }
+            catch
+            {
+                input.Dispose();
+                throw;
+            }
+        }
 
         /// <summary>
         /// Create file corresponding to <paramref name="entry"/> in current directory and open it

GameRes/FileSystem.cs

@@ -730,8 +730,16 @@ namespace GameRes
                 return arc_fs.Source.OpenImage (entry);
 
             var input = fs.OpenBinaryStream (entry);
+            try
+            {
                 return new ImageFormatDecoder (input);
             }
+            catch
+            {
+                input.Dispose();
+                throw;
+            }
+        }
 
         public static Stream OpenStream (string filename)
         {