Edit/Extend command

 From:  tyglik
321.1 
Hi Michael,

When I make a surface by using Construct/Planar command with a planar curve (e.g. rectangle) as an input, I'm not able to use this trimmed surface as a boundary object for creating the line extension (Edit/Extend). This is the same for any cap that is created by Construct/Planar command. Is it a bug?

Petr