Created attachment 13410 [details]
Thunderbird by konsole

This is the output of Thunderbird by konsole

Created attachment 13411 [details]
Terminal debug Thunderbird

This is the terminal debug of Thunderbird

Created attachment 13412 [details]
Temporally file

This is is the temporally file in my desktop, I can't attach the file because is empty...

I can't recreate the problem.

Try creating a new linux user and see if that user has the same problem.
That will show whether it's something wrong with the thunderbird configuration,
or a system wide problem, possibly a missing requires.

CC: (none) => davidwhodgins

I was unsure about the problem. This much is clear:
- create a new message.
- attach a PDF file
Does the attached PDF seem to be the right size?
At this point, no temporary file on desktop.

How do you then open the PDF attachment of an unsent message from within Thunderbird?
When you do so, it is at this point that the temporary desktop file appears?
Does opening the PDF attachment display it? Or just put the icon on the desktop?
Does opening the attachment leave it attached to the message, or remove it? Does the unsent message still show the original attachment?
Does the desktop 'copy' have the same size as the original attachment? You say you cannot [re]attach it: "I can't attach the file because is empty..." Why would you want to do this if you are trying to view a PDF already attached to a message?

CC: (none) => lewyssmith, tarazed25

About comment 5:

- Create a new message.
- Attach any pdf file with any size.
- Before send the message, test to open the pdf file, in my case with Okular, but I tried in Lxqt  with pdfview and appears the same issue.

I have this bug in various pcs, with various desktop environments, and this bug appears all.

I open the attach file for check that the pdf file is the pdf that I want send. 

I have maked this video for explaint it better.

https://ecloud.global/s/rpGFBoXGTEJPx3W

(In reply to Lewis Smith from comment #5)
> How do you then open the PDF attachment of an unsent message from within
> Thunderbird?

Right click on the pdf file at the bottom of the message compose window and
select open, to open it within thunderbird, which ignores the plasma settings.
(I have plasma set to use xpdf).

As I don't get the temp file on the desktop, I can't answer the rest.

Created attachment 13413 [details]
Thunderbird with a new complete folder profile.

Hi, 

I have created a new config of Thunderbird deleting the old folder. 

- I open a new message.
- I attach a PDF file.
- I open the PDF file and I see that Thunderbird recognize this file as HTML and create a temporally file in my desktop again as you can see in this attach.

(In reply to Dave Hodgins from comment #7)
Thanks for your input. I do not have Thunderbird, and have no wish to get bogged down in it.

> (In reply to Lewis Smith from comment #5)
> Right click on the pdf file at the bottom of the message compose window and
> select open, to open it within thunderbird, which ignores the plasma
> settings.
> (I have plasma set to use xpdf)
> As I don't get the temp file on the desktop, I can't answer the rest.
Ah, but you can in part. Does this viewing the unsent attachment affect it in any way? Does it remain intact, so that it goes successfully with its host message?

I notice you "open it within thunderbird", whereas Jose is opening it with an external application: "in my case with Okular, but I tried in Lxqt  with pdfview".

@Jose: can you do the same as Dave?

Why is Jose's experience so different - and consistently so? (Yet to watch the video).

Hi again!!

I have seen that this bug don't appears if I have as default application "Thunderbird" for open PDF files.

And I have checked that this bug doesn't of Mageia only, I have tested this in KdeNeon and Endeavour OS with the same results.

I have reported upstream in Bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1793932

(In reply to Lewis Smith from comment #9)
> Ah, but you can in part. Does this viewing the unsent attachment affect it
> in any way? Does it remain intact, so that it goes successfully with its
> host message?

It doesn't appear to have any impact on the message. The pdf view opens in
a separate thunderbird window, not a tab. Leaving that open and using the
first window to send the message, it is sent ok.

> I notice you "open it within thunderbird", whereas Jose is opening it with
> an external application: "in my case with Okular, but I tried in Lxqt  with
> pdfview".
> 
> @Jose: can you do the same as Dave?
> 
> Why is Jose's experience so different - and consistently so? (Yet to watch
> the video).

In thunderbird settings/General, under Files and Attachments, PDF was set to
preview in thunderbird.

I changed it to use xpdf, then created a new message and attached a pdf file.
The empty temp file is created in ~/Desktop, and viewing the pdf fails as
that is trying to view the empty file.

Sending the msg after the failed viewing does send the pdf, and it's ok on
the receiving end.

Jose, Please try changing the thunderbird setting for pdf back to it's default
of "Preview in Thunderbird".

As comment 10 shows this is an upstream issue, I suggest an errata entry with
"Keep thunderbird configured to use thunderbird to preview pdf files. Don't use an external application.".

Thanks for this research & suggestions.
And to Jose for his experiments & raising the upstream bug.

Jose: "I have seen that this bug don't appears if I have as default application "Thunderbird" for open PDF files."
Do you mean the desktop-wide default for PDF viewing (which would be bizarre, to use Thunderbird);
or as Dave noted:
"thunderbird settings/General, under Files and Attachments, PDF was set to
preview in thunderbird"
If the latter, I think we can close this, there is nothing we can do. The correction will filter through in the fullness of time (hopefully).

CC'ing Morgan (TIA !) re:
an errata entry with
"Keep thunderbird configured to use Thunderbird to preview pdf files. Don't use an external application. In Thunderbird settings/General, under Files and Attachments, PDF should be set to preview in Thunderbird."

Keywords: (none) => FOR_ERRATA8, UPSTREAM
Resolution: (none) => WORKSFORME
CC: lewyssmith, tarazed25 => fri
Status: NEW => RESOLVED

I see this as a minor problem, but as Thunderbird is used by many users it deserves a hint in errata.

Added a shorter note at end of
https://wiki.mageia.org/en/Mageia_8_Errata#Various_software

Keywords: FOR_ERRATA8 => IN_ERRATA8