Am 18.11.2012 23:13, schrieb Michael Heydekamp:

Am 18.11.2012 08:55, schrieb A.L.E.C:

On 11/18/2012 01:26 AM, Michael Heydekamp wrote:

I just realized that the whole thing is also related to the user config setting "Display HTML" in the "Displaying messages" section. If disabled, Roundcube DOES reply to the text/plain part (if at the same time "Compose HTML messages" is set to "Never").

Yes. This is by design. If you view the message as HTML we use the same part for response. It's because text and html part may differ.

Well, they HAVE to differ by definition, IMO. Otherwise it wouldn't make
sense to have a text/html and a text/plain part, if there would be nil
difference.

But the text part of a HTML message is by far the better formatted and
"quotable" part than the HTML part, being stripped and re-formatted by
Roundcube or any other MUA.

Why should it be better formatted (Except maybe in some very exceptional cases where both parts have been created individually)? Usually the text part is just a stripped and reformatted version of the HTML part, only that this has already been done by the mail client when the HTML message was composed. So where is the difference...? 

See the newsletter that I attached to my original post, the quote is just ridiculous.

I think it's better to use on reply the same part which was viewed.

And I think that the text/plain part is there for some reason: One of them
being that it should be the one to be quoted if composing a text/plain
reply. (The other one being that it can be viewed with MUAs not being
HTML-capable.)

No, you need to use the part being displayed for quoting when composing a reply. As has been said before text and html part sometimes differ, not only in formatting but also the content may be completely different! E.g. it could contain just a link to read the newletter online or be just some default text, etc. 

b) Vice versa ("Display HTML" being enabled) I do NOT get a link to display the text/plain part. But if this link would exist, THIS could do the trick with regards to if I will reply with a HTML or a plain text message (and which part of the message will be quoted). At least I should have the chance to VIEW the text/plain part, even if "Display HTML" is enabled. I do not have a final concept at hand, but would you agree that some redesign is needed here...?

I agree, it would be good to have a html/text switching button in message preview pane. 

Yes, this is something which I believe is really missing. One option could be to show the unused part as attachment and clicking on it chooses this part.

Manfred