charset=x-user-defined

[Christian Riechers]

I received the following message from another reader of the
mozilla.support.firefox group:

[excerpt quote=\"
I'm using a newsreader on Android and your posts in the 'Firefx on
android' thread don't appear correctly.
Each one just appears as:
x-user-defined
I can see them fine on PAN, but I can't see that header, if it's there.
I surmise that:

1 The android agent has a bug - it hits that header, treats it as the
post text, and falls over the next header.

2 Pan sees the header and ignores it.

Is that header there? Is it valid (lower case x)?
If you think it's valid I'll send a bug report to Piao Hong who wrote
the newsreader."
\" /]


There is indeeed a x-user-defined field in the header of the news post:

Content-Type text/plain;charset=x-user-defined;format=flowed

But I have no idea where this comes from or what it actually means.
Looking through some of my older posts I do see the same thing, but
there are also other posts with charset=UTF-8.

I'm composing in plain text, and the character set is set to UTF-8 for
outgoing mail. So charset=x-user-defined is nothing I've set deliberately.

It seems to be valid, as nobody else has complained about it before. Or
it may well be a bug in Thunderbird.

Sending myself an email I do see:

Content-Type text/plain;charset=UTF-8;format=flowed

in the header. Perhaps it's related to the charset used by the
sender? Anyone knows what this is all about?
Thanks.

--
Christian

[Ralph Fox]

Perhaps this:

Right-click on mozilla.support.firefox in the left pane.
Choose 'Properties' from the right-click menu.
On the 'General information' tab, ensure these two settings are set as
follows:

Default character encoding: --- Western (ISO-8859-1)

[ ] Apply default to all messages --- NOT checked


--
Kind regards
Ralph

[Christian Riechers]

Thanks. What would be the effect of doing this? For
mozilla.support.firefox this was set to Western (ISO-8859-15), not User
Defined.

--
Christian

[Dave Royal]

On Sun, 06 Oct 2013 18:53:38 +0200, Christian Riechers wrote:

Looking back through the threads still on this machine I see that your
posts with charset=x-user-defined are in the minority. The only common
factor I can find is that they are all on Linux, and they are all
replies. But these two conditions are not sufficient. And I can't see
anything common to the posts being replied to, which might influence the
character set.

An example on this NG: e.g. "Can one customise the Toolbar..." on 28/7
which has one post with this effect, and one without.

Do you use only one Linux machine, and only one profile on it?

(My Android newsreader can neither see nor reply to these posts. I've
raised a bug.)
--
(Remove any numerics from my email address.)

[Christian Riechers]

I do primarily use the Linux machine, but not necessarily with the same
profile.
My best guess is that this is related to the 'Default character
encoding' setting in the group properties as Ralph Fox suggested.
I'm not having access to the Linux machine right now, but will check the
setting once possible.
This post is from a Win 7 machine, and if the theory is correct, you
should be able to read this using PAN.
But the exact meaning and effect of the setting in the group properties
still isn't exactly clear to me.

--
Christian

[Dave Royal]

On Mon, 07 Oct 2013 20:13:31 +0200, Christian Riechers wrote:

> I do primarily use the Linux machine, but not necessarily with the same
> profile.
> My best guess is that this is related to the 'Default character
> encoding' setting in the group properties as Ralph Fox suggested.
> I'm not having access to the Linux machine right now, but will check the
> setting once possible.
> This post is from a Win 7 machine, and if the theory is correct, you
> should be able to read this using PAN.
> But the exact meaning and effect of the setting in the group properties
> still isn't exactly clear to me.

There's also the default character encoding in Prefs > Display >
Formatting > Advanced - though I don't know if that also applies to
Newsgroups. My guess is that your default is UTF-8 because that's what
you use when you start a thread - in both Linux and Windows.

In PAN I have no problem - it ignores this unusual charset field. I
suspect that the bug in my Android newsreader is that 'x-user-defined'
looks like a header prefix.

Unless you can find this 'x-user-defined' charset in your prefs I suspect
that this is a bug in TB. But a very minor one since it probably only
affects users of one buggy newsreader. TB presumably has to work out what
charset to use on replies, and I suspect that's where the problem is. But
I'm guessing.

[Christian Riechers]

Checked also on my primary Linux machine. Same thing as on the Win 7
machine, the 'Default character encoding' setting in the properties for
mozilla.support.firefox was already set to Western (ISO-8859-15).
I've now changed it to UTF-8 on both.

So I still don't have an idea how 'charset=x-user-defined' got into the
header for some of the newsgroup posts.

--
Christian

[Ralph Fox]

On Sun, 06 Oct 2013 22:59:14 +0200, Christian Riechers wrote:
> On 06.10.2013 21:25, Ralph Fox wrote:

[[---snip---]]

>>
>> Perhaps this:
>>
>> Right-click on mozilla.support.firefox in the left pane.
>> Choose 'Properties' from the right-click menu.
>> On the 'General information' tab, ensure these two settings are set as
>> follows:
>>
>> Default character encoding: --- Western (ISO-8859-1)
>>
>> [ ] Apply default to all messages --- NOT checked
>
> Thanks. What would be the effect of doing this? For
> mozilla.support.firefox this was set to Western (ISO-8859-15), not User
> Defined.

Those are the default settings, which are not known to cause problems. I
would not expect 'Default character encoding' by itself to cause
problems, only if used in conjunction with turning on "Apply default to
all messages".

I cannot replicate the problem here in Win8, even when composing the
same reply to the same messages. Are your messages going out through a
local proxy on Linux? I have heard of software automatically replacing
charset=windows-1252 with charset=x-user-defined, because the software
author had a dislike for windows-1252.


--
Kind regards
Ralph

[Christian Riechers]

No, definitely no proxy here.

--
Christian