bug#6385: A slightly less aggressive fit-window-to-buffer

[martin rudalics]

> What I saw was the even  2 lines high buffer made fit-window-to-buffer
> delete sibling windows. All the time - but... I thought I knew how to
> reproduce it. So I did not write any test procedures, I was just a bit
> irritated. A mistake.
[...]
> This function killed all other siblings even if it just actually needs
> two lines if certain conditions are met. (Those I tried to describe.)
>
> So this was just a desperate attempt to stop that. I do not know what
> to do at the moment. I will try to reproduce this and look a bit
> closer at it later.

Deleting other windows when resizing was a misguided feature.  I don't
do that any more for quite some time and didn't miss it yet ;-)

In any case, the issue whether a position is visible in a window is a
priori not related to the issue whether resizing is allowed to delete
any windows.  You patch might handle a few cases, accidentally ...

martin