indent-tabs-mode setting in Emacs's dir-locals.el

[Dmitry Gutov <dgutov@yandex.ru>]

On 12/16/2015 03:00 AM, Paul Eggert wrote:

> I observe problems in this area when changing code (which changes
> indentation) and then changing it back (i.e., not undo, but make a
> further change that undoes most or all of the original change).

Indeed, that would do it.

> In this
> case Emacs changes tabs to spaces, assuming the .dir-locals.el settings
> already mentioned.

Yup. But it only makes a difference if Arthur hasn't customized 
indent-tabs-mode to nil in his Emacs already.

Having a project-wide setting, however, lets us hope that someday the 
indentation style will be uniform, and this problem won't occur anymore.

> Yes, of course.  Here, though, a two-line changed ballooned into a
> 23-line change. The first 2 lines of the ballooned change were real, and
> the other 21 lines were tabs-to-spaces only.

I usually try to undo such hunks with `diff-hl-revert-hunk'.