bug#15577: 24.3; dir-local variables not applied when switching major-mode

[Glenn Morris]

yary wrote:

> If I create a ".dir-locals.el" that applies to all major modes, such as:
>   ((nil . ((tab-width . 3))))
> It works when first opening any file under that directory- good. But, if
> I switch the buffer's major-mode, it loses the directory-local
> tab-width -

File-local variables behave in the same way.