often I want to copy the history stack from one image to the next in the darkroom view. Currently, I go to the lighttable and use the history stack module there to copy and paste the stack from one image to the other. Is there a way (e.g. a shortcut) to do this directly in the darkroom?
As others have said, ctrl c and ctrl v work in the darkroom. You will want the filmstrip enabled to make this easier. Just one word of caution: the operation can be done with just the mouse hovering over the image thumbnail in the filmstrip. So if you click on a thumbnail then move the pointer over another thumbnail before you do the copy or paste operation, it will apply to the image you have hovered over, not the one you clicked. Once you get used to this behaviour, it’s very easy to do operations like copy/paste and rejecting photos by just hovering over thumbnails in the filmstrip.
Personally I do ctrl-shift-C as it allows me to select which parts of the history I want to copy from one image to the other. Ctrl-shift-V works in a similar fashion as well. I know Todd already mentioned it, but I find it so much more useful than a blind ctrl-c approach.