> Yet, the displayed information is not completely stable. What I mean is
> that if I move the cursor in another buffer, the echo area is sometimes
> cleared. It's a little bit annoying. How could I fix this without
> advising several cursor displacement function ?
I don't know enough about this code to be able to answer. You're going
to have to investigate which code does this "clearing" and what calls
it, to then be able to figure out what's the best way to address the
problem (we can change the C code for that in 24.2 if needed).