Re: set-window-start

[Richard Stallman]

    In Emacs 20.7, (set-window-start WINDOW POS) makes POS the window
    start, as documented.  In current CVS and in 21.3, it makes the window
    start either at the _beginning_ of the line POS is on, _or_ at the
    beginning of the _next_ line, according to rules that are not clear.

I think it is a bug.  There is a mechanism that is supposed to assure
that when Emacs chooses a new window-start, it tries to choose
the start of a line.  That mechanism should be disabled when you
specify a window-start explicitly.  Perhaps the code to disable
it is not working right.