Adds a new menu item
Select→Layer to selection
which creates a selection that exactly matches the boundaries of the current layer.
2012-08-08: Added the fixes by Aralox thanks :-)
See also http://flashingtwelve.brickfilms.com/GIMP/Scripts/layer-select.scm by saulgoode.
Creates a frame/border outside the image; the frame mirrors the original image.
The menu item appears in
Adds a menu option
Layer→Scale and move layer to canvas
which scales the layer to canvas size, and moves it so it exactly covers the canvas.
Newest version always at https://github.com/unhammer/gimp-fu
Unless otherwise noted, the rights for the individual plugins are with their respective authors. Logo image by Jakub Steiner.