Buffer can forget fill column

[<TIM at MIT-MC>]

In ZWEI in Release 5.1, Experimental MIT 1.4, FEP 18, on Lisp Machine Janis Joplin (3600):

When a buffer that is not associated with a file becomes associated with
a file, it forgets its fill column if this attribute is associated only
with the buffer (does it forget other attributes too?).  For instance:

I am in *Buffer-1* and start typing away.  Then I want to fill a
paragraph, so I set the fill column and specify that it is only for
this buffer (rather than for the Mode or Globally).  Then I write
the file out using c-X c-W.  The next time I do a fill paragraph,
the fill column has been set to the default!

By the way, it might be useful to be able to associate a fill column
with a particular editor window.  This way if you have a window that is
some funny size, all the buffers that you edit in this window will be
filled according to the size of the window.