Since PasteUpMorph>>drawOn: already does the background fill and draws
submorphs, this fix will result in the backgrond being filled twice, and
the submorphs being drawn twice.

Also, the implementation of drawOn: will also draw the grid form, which
is probably not something we want to have visible here.

I recommend my fix instead, but the trails form depth fix in
#createOrResizeTrailsForm should be included.













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