bug#5062: 23.1.50; image-toggle-display overwrites nxml-mode local key map

[Juri Linkov]

> Better would be to save the major mode, and then switch to
> "saved-major-mode + image-minor-mode".  No need to modify anybody's
> keymap.  And I think that image-minor-mode should only be used while
> displaying text: basically, image-toggle-display should toggle between
> image-mode and the other major-mode (complemented with
> image-minor-mode).
>
> That would be cleaner,

I see now how this is implemented with `doc-view-previous-major-mode'
in doc-view.  Perhaps we should "sync" this with image-mode to use
the same logic.

-- 
Juri Linkov
http://www.jurta.org/emacs/