Re: Diff 2 files with lines added at top of second file: confusing

> My first thought would be some autocmd or a manually-triggered
> mapping, would ":windo if &diff | 0 | endif" to ensure that all diff
> windows are at the top.

Thanks for the idea! Based on your suggestion, this is how I launch the diff now:
gvim.exe -d a.txt b.txt +"windo 0"

and things *seemed* to work, until I switch a and b:
gvim.exe -d b.txt a.txt +"windo 0"

and I run in the same issue...

Christophe