bug#20322: 25.0.50; indent-tabs-mode should default to nil

[Dmitry Gutov <dgutov@yandex.ru>]

On 04/14/2015 05:17 PM, Eli Zaretskii wrote:

> Each major mode can (and some already do) have its own default.

I can see ruby-mode and texinfo-mode set it to nil, which makes sense, 
but it also makes it harder for the user to configure everything in one 
place. Here's one complaint about it: 
http://emacs.stackexchange.com/a/9385/124

Personally, I'd only do that if the language can't handle the default 
value at all (like it's the case with Makefiles).

> If the customizations are due to language guidelines/culture, then
> setting this to nil in the major mode is TRT.

Maybe, but my point is that going by this logic most major modes would 
need to set it to nil. And then it'll just make sense to make it the 
default.

Note that doing that change in major modes will have pretty much the 
same problem as changing the default: users who got used to the current 
behavior. Only it'll make it harder to revert the change, because 
that'll need to happen in hooks now, or in file-local variables.