ToImage() methods incorrectly dispose of underlying MemoryStream. about exiflibrary HOT 5 CLOSED

Also, the remarks regarding keeping the stream open are valid all the way back 
to the 2.0 framework.

http://msdn.microsoft.com/en-us/library/93z9ee4x(v=vs.80).aspx

This issue was closed by revision r98.

Thanks for the detailed  bug report. I fixed it as you suggested. However, a 
quick test shows that the source stream is not automatically disposed when the 
Image is disposed. It gets disposed during garbage collection when the stream 
finalizer is called. Here is the test code:

public class XStream : System.IO.FileStream
{
    protected override void Dispose(bool disposing)
    {
        base.Dispose(disposing);
        Console.WriteLine("Stream disposed");
    }

    public XStream(string filename)
        : base(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read)
    {
        ;
    }

    ~XStream()
    {
        Console.WriteLine("Stream finalizer called");
    }
}

static class Program
{
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {
        XStream xs=new XStream(@"C:\test.jpg");
        using (System.Drawing.Image img = System.Drawing.Image.FromStream(xs))
        {
            Console.WriteLine("Image created");
        }
        Console.WriteLine("Exiting");
    }
}

I get the following output:

Image created
Exiting
The thread 0x1748 has exited with code 0 (0x0).
Stream finalizer called
Stream disposed

This is probably not a big deal though; since we have a MemoryStream.

I Guess you could dispose the stream if you managed the full life-time of the 
Image but as you're an API and you're passing the image back to client code you 
can't know when the lifetime of that object.

I've just had a look through Image.FromStream and it doesn't seem to track the 
Stream object within the framework. It wraps it in a GPStream and calls into 
the native gdipluss.dll . The way that the stream is (not) managed and therefor 
finalized by the GC must be (i guess) by design.

As a side note, the image itself is IDisposible, so that should be disposed 
appropriately which would remove the (last?) reference to the stream, allowing 
it to be collected.

Thanks for the quick fix.