NAME
        CurrentChunk -- get context node for current chunk. (V36)

   SYNOPSIS
        top = CurrentChunk(iff);
        D0                 A0

        struct contextnode *currentchunk(struct iffhandle *);

   FUNCTION
        Returns the top context node for the given iffhandle structure. the top
        context node corresponds to the chunk most recently pushed on the
        stack, which is the chunk where the stream is currently positioned.
        The contextnode structure contains information on the type of chunk
        currently being parsed (or written), its size and the current
        position within the chunk.

   INPUTS
        iff - pointer to iffhandle structure

   RESULT
        top - pointer to top context node or NULL if none

   SEE ALSO
        pushchunk(), popchunk(), parseiff(), parentchunk(),
        <libraries/iffparse.h>