[comp.sys.mac.programmer] Window Structure Region question

upstill@pixar.UUCP (Just because I'm paranoid doesn't mean they're not out to get me) (03/23/89)

    It's a simple question, really, because the problem is simple: I can't
get the SaveOld()...DrawNew() pair in the Window Manager to work to save
my life.
    Here's the deal: I want to redefine the structure region of a window
in my application when I feel like it, as opposed to at the behest of my
WDEF.
    I carefully create the appropriate structure and content regions by
    -- opening up another window,
    -- opening up a region
    -- drawing the region outline
    -- closing the region
    -- closing the second window.

    So now I have two nice new regions, 'structure' and 'content'.  Then I say

    SaveOld( &mywindow );
    CopyRgn( structure, mywindow.strucRgn );
    CopyRgn( content, mywindow.contRgn );
    DrawNew( &mywindow, TRUE );

    Inside Mac claims that this will update a region obtained by XOR'ing the
old and new regions.  Instead, it doesn't seem to recognize much of anything
inside the new region.  Sometimes the new region obscures stuff behind it,
sometimes not.  I have tried doing the above procedure when the window was
invisible, then Show'ing it, to no avail.  Nothing I have thought of seems
to do the trick.  
    Are there any ROM-nuts out there who can diagnose this problem?  Many
many thanks if so.

Steve Upstill