Paste as Image - wrong dimensions (bug?)

[marco-gimp]

GIMP 2.10.20 (revision 1)
Paste as Image - wrong dimensions (bug?)

   Select 3500 x 4500

   Paste as Image

   New Image = 3522 x 4500


To test this
I created a new image at 3500 x 4500
Then pasted into selection

This time, there was a gap at the bottom of the image - the checkerboard was visible.

The image appeared to have shrunk to the width, and therefore shrunk the height.

Either way, the selection size was clearly 3500 x 4500 yet it will not paste at those dimensions.

[Kevin]

I can't reproduce this BUT I am doing something you've not included in your instructions:

Image is 3600x4800

Make selection 3500x4500 by typing into the tool options
Copy
Paste as New image

New image is 3500x4500

[rich2005]

Works here, kubuntu 18.04 / Gimp 2.10.20 Select -> Copy -> Paste as new image.

The only way I get an increase in size is when Feather Edges is enabled but that gives a margin on all sides.

[marco-gimp]

Thanks for those responses.

@ Rich2005 Yes it was the Feathered Edges wot done it

I've just recreated the scenario.

The likely reason why the 22 pixels only appeared on the width is because I first scaled up the original landscape image to 4500 height.
This was to define the scale 35 / 45  (I was happy with the height content)

Consequently, I selected the height at 0 & 4500
Then the width was centred around the subject @ 3500
The selection editor showed image size as 3500 x 4500.

Copy Visible - Paste as New Image = 3522 x 4500

This test was repeated with feathering OFF and 3500 x 4500 was correctly pasted.

Another Test

The test was repeated at 3500 x 4400
Ie. all the selection was within the original image.

Interestingly enough, I learned a funny quirk.
With feathered Edges off it pasted as 3500 x 4400

Last test was to switch ON Feathered Edges, so I clicked the box, and the x appeared.
Copy and pasted but NO CHANGE?

I returned to feathered edges, changed the radius then copy and pasted = 3526 x 4413

From this, it appears that simply clicking the box doesn't make the switch.
It's rather like changing a dimension, without hitting enter, or clicking in another box.

Debate

I can see both arguments - 
Feather edges but don't lose data
Or 
Select to create an image to dimensional specification

Of course, once you know how it works, then you can do the maths to achieve the final image (subtracting feathering radius).

Overall though, I'd side with pasting the stated dimensions, because very often one is creating an image to dimensional specs.
Rarely if ever, is one concerned with a few pixels loss to feathering and hence why feathering might be chosen.

What do you think? 
 

[Ofnuts]

The only sensible behavior is to include everything. You can suppress the feathering beforehand, while in the general case restoring not-copied partially transparent pixels is much harder (because there are many cases where this won't be a plain feathering, but for instance anti-aliasing pixels).