v3.x: NDC.Inherit is broken

[jberg7]

Hi team! It looks like b5f6ea2 broke NDC.Inherit(). By way of example:

var context = NDC.CloneStack();
NDC.Inherit(context);

Gives this error:

   System.InvalidCastException : Unable to cast object of type 'System.Object[]' to type 'StackFrame[]'.
  Stack Trace:
     at log4net.Util.ThreadContextStack.set_InternalStack(Stack value) in /home/alle/git/apache/logging-log4net/src/log4net/Util/ThreadContextStack.cs:line 191
   at log4net.NDC.Inherit(Stack stack) in /home/alle/git/apache/logging-log4net/src/log4net/NDC.cs:line 160

I understand that the use of NDC has been deprecated for some time, but from looking at the code it seems the intent of log4net 3 has been to maintain backwards compatibility, so I think this behavior is a bug.

(On a related note, is there an appropriate replacement for the above, other than writing my own custom copy mechanism to ThreadContext.Stacks["NDC"].Pop() into some temporary array, and then later on .Push() back onto the stack?)

[FreeAndNil]

@jberg7 thanks for reporting.
I've created #246.
Does that fix you problem?

You are right, there is currently no other replacement in log4net.

[jberg7]

Thanks for the super quick turnaround! From the tests in your PR it looks like this would fix my problem :)
I'll keep an eye out for 3.1.1.

[FreeAndNil]

@jberg7 can you test with https://github.com/apache/logging-log4net/releases/tag/rc%2F3.2.0-preview.1 ?