We had an external user (ESO) request a change to GkiKernel?.getStdin/out/err() so that they return the self.stdin/out/err members over the default arg, in the case when the local members are defined and pass the isatty() test. Eso is redirecting PyRAF i/o to use it embedded within their application.
Because PyRAF scripts can be run via redirection and not (interactively), it is difficult to tell ahead of time what this might break. Logically, the change will only affect the case where a defined non-tty default is used in conjunction with a tty-like local attr. In this case, now the local attr would be returned instead of the default. This seems to be in keeping with the idea of default args, but it s unclear if the GkiKernel? functions are being called in "expected" ways.
