[idd] skip copies for static frames

Treat IddCx's single empty dirty rectangle as no image update instead
of promoting it to full damage.

Preserve pending damage and format changes, and fall back to full damage
when legacy move regions are present.

idd/LGIdd/CInteropResource.cpp

@@ -154,6 +154,7 @@ void CInteropResource::SetDirtyRects(const RECT * dirtyRects, unsigned nbDirtyRe
     return;
   }
 
-  memcpy(m_dirtyRects, dirtyRects, nbDirtyRects * sizeof(*m_dirtyRects));
+  if (nbDirtyRects)
+    memcpy(m_dirtyRects, dirtyRects, nbDirtyRects * sizeof(*m_dirtyRects));
   m_nbDirtyRects = nbDirtyRects;
 }