bug#13887: 24.3; doc-view will render blurry images when image-magick is available

[Stefan Monnier]

> +        (unless (eq (window-buffer) (current-buffer))
> +          (set-window-buffer (selected-window) (current-buffer)))

This can't be the right fix: doc-view.el is just a major-mode that
controls how a particular buffer is displayed, and not which buffer to
display in which window.

[ I see Tassilo has a better patch already, so I'll let him take care of
  it, but I just wanted to point out "the obvious".  ]


        Stefan