1

Closed

null reference on a Form, where an object should be

description

While working towards an update binary release, noticed the following despite all unit tests passing (!). From the vignette on the introduction:

Likely due to changes to clear up COM object memory.
library(rClr)
clrLoadAssembly("System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")
f <- clrNew("System.Windows.Forms.Form")
clrSet(f, "Text", "Hello from the '.NET' framework")
clrSet(f, "Text", "Hello from the '.NET' framework") # the CLR object is now null : stack trace in .NET; null reference exception.
Closed Sep 20, 2013 at 11:20 PM by jperraud
Fixed at rev 199 (3f81e3b4d7fd)

comments

jperraud wrote Sep 20, 2013 at 10:18 PM

Need to reproduce elsewhere. I have noticed the behavior on an object other than a form (a ModelRunner) at work. There is probably something under clrSet that triggers the discard of the GC handle when cleaning up variants or so-called "safearrays"