Wanted feature for curves: a render-time resolution. This option is

located under the 'def resolu' button. If not zero, it assigns this
resolution to a curve on render.
Also copies with ctrl+c menu.

source/blender/src/editobject.c

@@ -2850,6 +2850,7 @@ void copy_attr(short event)
 						cu1= base->object->data;
 						
 						cu1->resolu= cu->resolu;
+						cu1->resolu_ren= cu->resolu_ren;
 						
 						nu= cu1->nurb.first;