Re: Visual line mode in email citation

[Stefan Monnier <monnier@iro.umontreal.ca>]

> Trying to use the visual line mode in place of longlines isn't working
> very well.  There are no soft line breaks.   So, we end up citing the
> entire paragraph as a single line.  This is supposed to be ok.
> Mail clients like Thunderbird know that the entire paragraph is being
> cited and put citation marks on all of it when they do word wrapping.

> But, VM and Gnus, depending on Emacs visual-line-mode, have no idea of
> what is going on.  They end up putting the citation prefix on the
> first line of the paragraph, and the remaining lines remain uncited.
> Like this paragraph, for example.

> Can the visual line mode be taught some email citation issues?

This was discussed here a few days ago: the word-wrapping performed by
the display engine makes indeed no attempts to recognize citation
prefixes (nor indentation), and given the level at which it works, it's
better that it doesn't try to do that.  OTOH it does provide hooks
(more specifically the `wrap-prefix' text-property), which Elisp code
can use to make this wrapping do the right thing.

IOW, some Elisp code somewhere needs to add a `wrap-prefix' to each line
specifying the citation/indentation/fill prefix to use.  This should
most likely be done by a function passed to jit-lock-register and which
then uses something like fill-context-prefix.

I'd welcome a patch that provides such a function (e.g. in fill.el) and
maybe visual-line-mode could/should use it, but at least Gnus's (and
VM's) message display code should use it.


        Stefan