automatic-hscrolling

automatic-hscrolling is a variable defined in `frame.el'.
Its value is

t

• This variable is an alias for `auto-hscroll-mode'.
• This variable is obsolete since 22.1;
  use `auto-hscroll-mode' instead.

Documentation:
Allow or disallow automatic horizontal scrolling of windows.
If non-nil, windows are automatically scrolled horizontally to make
point visible.

You can customize this variable.