Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

> So maybe a simple fix is the patch below, but I'm not sure it's always
> the right thing to do (and the width won't be automatically updated when
> the (line-number-display-width) changes).

[...]

> -	   (ncols (/ window-width font-width)))
> +	   (ncols (- (/ window-width font-width) (line-number-display-width))))

I tried this patch in Emacs 28, and it didn't seem to help much.

To test

emacs -Q
M-x global-display-line-numbers-mode RET
M-x term RET RET
emacs -Q -nw