Re: Diff could also show the changes within lines

["Sebastien Vauban" <wxhgmqzgwmuf-geNee64TY+gS+FvcfC7Uqw@public.gmane.org>]

Hi Tom,

"Sebastien Vauban" wrote:
> Tom wrote:
>> Sebastien Vauban <wxhgmqzgwmuf@...> writes:
>>>
>>> And the results of the jury are:
>
>   (defun my/diff-refine-all-hunks ()
>     (interactive)
>     (condition-case nil
>         (save-excursion
>           (goto-char (point-min))
>           (while (not (eobp))
>             (diff-hunk-next)
>             (diff-refine-hunk)))
>       (error nil))
>     (run-at-time 0.0 nil (lambda () (goto-char (point-min)))))
>
> Yep!  This does work perfectly: all hunks refined, and pointer at beginning of
> buffer...
>
> Thanks a lot for your more than precious help!

After a couple of days using this, I've observed a very tricky collateral
damage in Gnus...

Let's assume I have received 5 mails:

--8<---------------cut here---------------start------------->8---
*   18 Sun 14:25   0.2k Foo  Mail #1 Hello
    18 Sun 14:25   0.4M Bar  Mail #2 How are you?
    18 Sun 17:58   6.9k Baz  Mail #3 [diff] Fix bug
    18 Sun 18:06   4.1k Baz  Mail #4 [diff] Fix doc
    18 Sun 18:27   3.1k Baz  Mail #5 I've done it
--8<---------------cut here---------------end--------------->8---

* = position of the cursor

... and I want first to read the 3rd one. I position the cursor on that one...

--8<---------------cut here---------------start------------->8---
    18 Sun 14:25   0.2k Foo  Mail #1 Hello
    18 Sun 14:25   0.4M Bar  Mail #2 How are you?
*   18 Sun 17:58   6.9k Baz  Mail #3 [diff] Fix bug
    18 Sun 18:06   4.1k Baz  Mail #4 [diff] Fix doc
    18 Sun 18:27   3.1k Baz  Mail #5 I've done it
--8<---------------cut here---------------end--------------->8---

... press RET, get a new buffer created on the mid-right pane, and read it.

--8<---------------cut here---------------start------------->8---
*   18 Sun 14:25   0.2k Foo  Mail #1 Hello           |
    18 Sun 14:25   0.4M Bar  Mail #2 How are you?    |
    18 Sun 17:58   6.9k Baz  Mail #3 [diff] Fix bug  | (contents of 3rd email)
    18 Sun 18:06   4.1k Baz  Mail #4 [diff] Fix doc  |
    18 Sun 18:27   3.1k Baz  Mail #5 I've done it    |
--8<---------------cut here---------------end--------------->8---

Then, as I always do, I simply press "n" to read the "next one" (4th)... but
Gnus displays me the 1st one!

Why?  Because the cursor has been positioned on the first line of my *summary*
buffer (on the left), after displaying the contents of the "Fix bug" email (on
the right).

Why?  Because diff-mode is called (as that email contains a diff), and some
some effect -- which I don't understand -- is that *the cursor is repositioned
onto the first line of the summary buffer* (while the code is supposed to be
executed in the other window, the one with the *contents* of the mail).

So, here, to reproduce the problem, I have to:

- have emails with diffs in them (otherwise, diff-mode won't be called)

- skip reading the first email (so that, clicking "n" does open the "next"
  unread email... from the current cursor position, which is wrong here...)

I know describing a dynamic behavior is not obvious per email. So, did you
understand the description of the problem, at least?

Do you understand why this is occurring, or have some helpful ideas?

Best regards,
  Seb

-- 
Sebastien Vauban