> I reproduced this bug with Emacs 26.1 and 26.1.90 using -Q option.
>
> When pressing 'g' (revert-buffer) in an *Occur* buffer, in the case of
> having `list-matching-lines-jump-to-current-line' set to non-nil, the
> function errors as it can't find orig-line.
>
> I'm attaching a patch that adds a guard to the list of guards before
> inserting the current line.

Eli, is it ok to install this submitted patch to the release branch emacs-26?
At least, it prevents the error signal.

I see that for Emacs 27 in master this feature is completely rewritten.
But still I found a bug in master that can be fixed with another patch.
The following patch is for Emacs 27: