How to copy a rectangle of pixels from a masked layer in Photoshop?

Question

Adobe Photoshop

What is the fastest way to copy a rectangle of pixels from a masked layer, but not all, but only part of the bounding mask (aka bounding box)?
For example, if there is a picture with rounded corners (using a mask), then I want to copy the same picture, but without rounded corners.
PS If it's still not clear what this is about, for example, on the PSD layout of the site there is such a picture:
https://www.awesomescreenshot.com/image/2724791/fa...
I need to pull it out of the layout and save it in a separate JPEG file. But I can't just select and copy it because of the rounded corners. Also, I can't just cancel the mask and copy the entire contents of the layer, because under it there is usually art of arbitrary sizes, cut off by the mask. The question is, what is the fastest way to copy exactly a rectangular image of the correct size from under the mask?

Answer 1

Turn off the mask (shift-click on the mask icon), copy the layer, turn the mask back on. I do not see a problem ... Or is this not the question?