RE: Invisible changes in ediff

[Drew Adams]

> > 4. If the current diff is too large for the windows then I 
> > use `C-v' or `M-v', possibly repeatedly.
> 
> How do you know for certain whether or not it is too large for the
> window?  How do you know for certain how many times to use them?

Again, I might not be understanding you correctly.

I can see the current diff (highlighted in both windows).  If it extends to the
end (beginning) of one or both windows then I use `C-v' (`M-v') to scroll the
windows a bit.

I do it again if the highlight still extends to the window end (beginning).

Perhaps try what I described to see if it is in fact related to what you are
asking about.  I might completely misunderstand what you're asking.