Annoying memory bug

[Fred Kiefer]

I am trying to hunt down a very hard to catch memory issue. It should be
easy to reproduce for anybody interested. Just start up Ink, open the
info panel and start up the memory panel by clicking on the icon. Now
press the update button a few times until things settle down.

If you keep on pressing update you will notice that only one value keeps
on changing. It is the amount of GSCBufferString objects at increases by
one every time you press the button. If you move the mouse a bit, it
will even increase more.

I was able to track down the lost string itself, it is
@"NSStringPboardType". And it is easy to see that the problem vanishes
as soon as you close the last open document. This means that the leak is
most likely related to the NSTextView and there to the pasteboard
handling. It also goes away when I comment out the contents of
validateUserInterfaceItem:, that way it was possible to track the
problem down to the call to
[[NSPasteboard generalPasteboard]
                        availableTypeFromArray: types]

It is the result value of this call that gets leaked. Now NSPasteboard
is implemented mostly as DO to the pasteboard server and here I am lost.
How could we leak memory here?

Fred