Re: org-src--contents-for-write-back : preserve original major-mode, and avoid mixing tabs and spaces in org-mode buffers

[Nicolas Goaziou <mail@nicolasgoaziou.fr>]

Hello,

Brent Goodrick <bgoodr@gmail.com> writes:

> I do not understand what is meant by "tailored for the source" which
> is the Org buffer. All of the indentation changes being made here are
> within the temporary buffer created by with-temp-buffer, which is
> using fundamental-mode which is not the same as either emacs-lisp-mode
> or org-mode. That is the wrong mode to be in when running `indent-line-to`
> function since it is that particular editing mode that the user has
> control over the `indent-tabs-mode` variable (typically from mode hook
> functions). So I conclude that the temporary buffer, at that point in
> execution, has to be in the mode of the language used when indenting.

This is not necessary. `org-src--contents-for-write-back' merely adds up
indentation to the existing one. In particular, it doesn't re-indent
lines. The indentation being added depends on Org mode (was the block in
a list? Is it a src block where special indentation rules apply...), not
on the major mode from the edit buffer.

However, you have a point, as we need to somehow retain the values of
`indent-tabs-mode' and `tab-width' from Org source buffer, since those
may differ from the ones used in the temporary buffer.

Also, calling `org-mode' again in the temporary buffer, in addition to
being slow, wouldn't preserve, e.g., local values from the source
buffer. So I think the best thing to do is to store `indent-tabs-mode'
and `tab-width' from source buffer and apply them back into the
temporary buffer.

I committed a change along those lines, along with tests, in the maint
branch. Does it fix the issues you were encountering?

Regards,

-- 
Nicolas Goaziou