How does one get Macsbug to trap when CopyDeepMask is called, then
disassemble that instruction?

I need to see if it is calling OffsetRect at some point depending on OS
8.1, versus 8.6

I am getting some strange behavior with CopyDeepMask in 8.1 vs 8.6, and the
only thing I can think is that in OS 8.1, CopyDeepmask is offsetting the
Mask rect to full left if it isn't. This results in some bad behavior when
I drag to the left of my image and adjust the source and mask rects.

I don't know for sure other than it looks like my mask rect is getting
offset something serious behind my back.

?

rc