av9ash/GitBugs huggingface dataset:
Bug: nsIStyleSheetService gets cached version on first loadAndRegisterSheet()
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-05 05:28:52+00:00
Resolved: 2024-08-17 07:52:35+00:00

Tested both in TB 78 and TB 88. Despite `nsIStyleSheetService` being a Gecko thing, this bug doesn't apply to Firefox.

Steps to reproduce:
1. Save a CSS file anywhere with any rule that you can notice when the code is applied. For example:
`* {color: blue}`

2. Get the file URI, like `file:///C:/test.css`.

3. Run the following code in Error Console, replacing the URI by the one you get in previous step:
`Cc["@mozilla.org/content/style-sheet-service;1"].getService(Ci.nsIStyleSheetService).loadAndRegisterSheet(Services.io.newURI('file:///C:/test.css'), 2);`

4. You'll see the style applied. Now remove it:
`Cc["@mozilla.org/content/style-sheet-service;1"].getService(Ci.nsIStyleSheetService).unregisterSheet(Services.io.newURI('file:///C:/Users/test.css'), 2);`

5. Edit the file, like replacing `blue` by `red`. Then save it.

6. Register the stylesheet again (step 3).

Text in TB should become `red`, but instead it turns `blue` again. If you unregister the sheet again and re-register, now you'll get the updated version.

So TB needs to apply the stylesheet twice to update it.
Bug: Recipients not restored when re-opening/editing a draft message [Add-on API: set/getComposeDetails]
Status: RESOLVED
Priority: --
Resolution: FIXED
Created: 2021-04-05 09:23:49+00:00
Resolved: 2021-05-14 16:40:58+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

As reported by a SignatureSwitch-user:
     https://github.com/4ch1m/mozext/issues/43

* open a new mail
* enter recipient (, subject, text)
* save as draft
* re-edit the draft


Actual results:

The previously entered recipient from the draft doesn't get restored.




Expected results:

The previously entered recipient from the draft should get restored.

This is probably yet another side-effect of the recently introduced pillification (see bug 1696765).
Bug: Intermittent comm/mail/test/browser/composition/browser_customHeaders.js | Found an unexpected  at the end of test run -
Status: RESOLVED
Priority: P5
Resolution: WORKSFORME
Created: 2021-04-05 10:38:25+00:00
Resolved: 2022-04-04 11:57:09+00:00

**Filed by:** mkmelin [at] iki.fi
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=335434393&repo=comm-central
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/VqdkCM4cTy-VchQgTvN1Ew/runs/0/artifacts/public/logs/live_backing.log

---
```
I think this isn't totally new, but low-frequency intermittent```
Bug: Main pane not accessible, blocked by hidden password prompt (Mac)
Status: RESOLVED
Priority: --
Resolution: DUPLICATE
Created: 2021-04-05 17:56:21+00:00
Resolved: 2021-08-03 04:30:05+00:00

88.0b2 (64-bit) I just updated on MacOS Mojave. The good news(?) is that the multiple password prompts seems to be fixed. But I can never get focus in my main window. On the bottom it says sending login info to yahoo.com. Before restart of TB, it said trying to login to a different server. It has been an hour!
Bug: "paste without formatting" includes indenting when pasting into a html reply
Status: UNCONFIRMED
Priority: --
Created: 2021-04-05 22:37:54+00:00
Resolved: 2021-04-06 15:36:51+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

Pasting from a LibreOffice Write document a paragraph with an indented style into a reply to a HTML email chain, "paste without formatting".
Format->Paragraph->Paragraph does not allow removal of the indent.
The paragraph format is a reverse hanging indent, with the first line fully left and wrapped lines indented (before text = 0.5", after text = 0", first line = -0.5").


Actual results:

The pasted text's font is set to that of the email reply, but the paragraph format remains instead of matching that of the reply.
Decrease Indent fails to remove the reverse hanging indent.


Expected results:

Text pasted-without-formatting should retain only the unicode characters, stripping the font and paragraph formats.

ALSO the actual paragraph formatting should be viewable and editable, not just selectable (format>paragraph>paragraph vs format>paragraph>body text does not encompass indents).

Thunderbird 88.0b2 x64 on linux mint.

Many thanks
Bug: [Windows] When selecting a phone number type in the address book, the text is white-on-white.
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2021-04-06 05:44:41+00:00
Resolved: 2021-04-19 11:41:10+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

1. Open Thunderbird, with dark theme enabled.
2. Open the Address Book in Thunderbird, version 78.9.0
3. Create a new contact, or edit an existing one.
4. Under the "Contact" tab, edit or create a new phone number.
5. Attempt to select the phone type, or home or work.


Actual results:

The text is white-on-white, making it difficult to select the correct type.


Expected results:

The text should be black-on-white.
Bug: Dragging a mailing list from one address book into another will remove all list members (empty list).
Status: RESOLVED
Priority: P2
Resolution: FIXED
Created: 2021-04-06 09:14:14+00:00
Resolved: 2021-06-10 11:56:00+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0

Steps to reproduce:

1. Create a list inside one address book.
2. Move the list with mouse to the other address book.

Happened in Thunderbird 78.9.0 (32-Bit)


Actual results:

All entries in the moved list are delete.


Expected results:

The entries should not delete.
Bug: Pasted pictures into the body of emails, the recipients do not receive them..
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2021-04-06 12:07:18+00:00
Resolved: 2021-04-24 08:02:34+00:00

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

When I paste a picture, (any type), into the body of an email, it shows in my send window, but is not delivered to recipients.

Mac OS 10.15.7

Thunderbird Ver  78.9.0   64 bit


Actual results:

My recipients do not receive picture posted in the body of the email, photos sent as an Attachment work normally.   Screenshot provided.


Expected results:

Photos should appear in the body of the email as they have in the past
Bug: Some folder icons not shown after restart following a crash
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2021-04-06 12:35:29+00:00
Resolved: 2021-11-06 12:17:48+00:00

I started TB after a crash, and a few folders did not have their icons.

At first I thought maybe these were all folders I had set to custom color, but on checking, no, most did not have a color set.

So I'm at a loss to explain why.  icons appeared on a second startup
Bug: Shutting down Thunderbird right after opening it will result in account login failure message. Quitting should terminate operations in progress.
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2021-04-06 13:02:37+00:00
Resolved: 2023-05-08 20:59:46+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36

Steps to reproduce:

1. Open Mozilla Thunderbird.
2. Exit it as soon as accounts are trying to connect.


Actual results:

Mozilla Thunderbird exits but a failed login message appears asking if you want to try again.


Expected results:

For Mozilla Thunderbird to exit without this message.
Bug: Crash in [@ shutdownhang | DefaultFreeTable].  McAfee?
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2021-04-06 14:30:02+00:00
Resolved: 2021-05-20 17:58:33+00:00

Crash report: https://crash-stats.mozilla.org/report/index/250bdadd-0bad-4597-9b56-f73640210406

MOZ_CRASH Reason: ```MOZ_CRASH(Shutdown too long, probably frozen, causing a crash.)```

Top 10 frames of crashing thread:
```
0 nss3.dll DefaultFreeTable nsprpub/lib/ds/plhash.c:42
1 nss3.dll PL_HashTableDestroy nsprpub/lib/ds/plhash.c:126
2 nss3.dll ShutdownCRLCache security/nss/lib/certdb/crl.c:1220
3 nss3.dll nss_Shutdown security/nss/lib/nss/nssinit.c:1154
4 nss3.dll NSS_Shutdown security/nss/lib/nss/nssinit.c:1221
5 xul.dll mozilla::ShutdownXPCOM xpcom/build/XPCOMInit.cpp:752
6 xul.dll ScopedXPCOMStartup::~ScopedXPCOMStartup toolkit/xre/nsAppRunner.cpp:1278
7 xul.dll mozilla::UniquePtr<ScopedXPCOMStartup, mozilla::DefaultDelete<ScopedXPCOMStartup> >::reset mfbt/UniquePtr.h:302
8 xul.dll XREMain::XRE_main toolkit/xre/nsAppRunner.cpp:4829
9 xul.dll XRE_main toolkit/xre/nsAppRunner.cpp:4866
```
Bug: Dark theme doesn't use the right colors
Status: RESOLVED
Priority: --
Resolution: FIXED
Created: 2021-04-06 20:25:49+00:00
Resolved: 2021-04-08 05:09:43+00:00

Text color for the active tab and the tree folder now use `rgb(212,212,212)` instead of `#f9f9fa`.  It seems to have been introduced by https://hg.mozilla.org/comm-central/pushloghtml?fromchange=d310d9c9341cfa0c7b4ad31463a69b545549f600&tochange=9cca2363d7e1537b736b911b766cdf950ad68b9b

**Edit**

It seems like a lot of other elements in the UI are affected by the changes related to upstream/Proton.
Bug: Matrix chat entry in address book not correctly saved
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-06 20:40:41+00:00
Resolved: 2024-11-12 12:02:58+00:00

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

In the Edit Contact window, I clicked the Chat Name field in an address book entry, intending to add my friend's Matrix messaging address.


Actual results:

The UI switched to the Chat tab, which has blank fields for 9 specific instant messaging systems, none of which are the Matrix network.


Expected results:

It should either offer a field for a Matrix network address, or allow me to add a custom one myself.

Matrix addresses look like this: @username:example.com

See also: https://matrix.org/
Bug: [Proton] Broken notifications with Proton enabled
Status: RESOLVED
Priority: --
Resolution: FIXED
Created: 2021-04-06 21:36:27+00:00
Resolved: 2024-10-28 13:09:09+00:00

I'm not sure if this should be in Upstream Synchronization or Theme.

I put this in theme because other than the obvious issue of multiple notifications not stacking properly, it highlighted an issue with the message header.
The `<table>` containing the Subject line grows vertically and center aligns the subject text but not the label.
The subject text should remain with a regular alignment like the label.

To easily recreate this issue you can save a draft with an embedded remote image.
Bug: randomly scrambled messages when browsing in 3-pane view - sometimes messed up threading, sometimes show the contents of a different email than selected message
Status: REOPENED
Priority: --
Created: 2021-04-06 21:57:14+00:00
Resolved: 2024-02-05 07:37:16+00:00

I'm sorry, I don't know how to usefully report this bug. :( But it's been showing up more frequently lately (it's been around for years) so I'm going to try.

Sometimes Thunderbird scrambles up messages. For example, I'll click on one message header in the messages list, but it'll show the contents of a different email.

(Sometimes also it scrambles the threading, mixing up different threads into some kind of frankenstein thread. I'm not sure if that's related.)

I have no idea how to reliably reproduce this, but it seems the MBOX isn't affected, because the “Repair Folder” button fixes it. I've seen it most often (that I recall) in my IMAP account. (I also have a POP3 account... I can't remember if I've ever seen the problem there.)

If there's some kind of file that would be useful to attach here next time it happens, let me know, and I'll try to capture it.
Bug: Ctl+U does not show message source
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-07 04:14:09+00:00
Resolved: 2021-08-22 14:58:36+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:88.0) Gecko/20100101 Thunderbird/88.0

Steps to reproduce:

While a message was showing, typed CTL+U


Actual results:

A window opened but it was never filled with the source.
If I went to the menu>View>message source the window opens with the source.


Expected results:

window should have opened with the source.
Bug: delete folder fails. error "Prompter: internal dialogs not available in this context. Falling back to window prompt. Prompter.jsm:1033"
Status: NEW
Priority: --
Created: 2021-04-07 10:50:08+00:00
Resolved: 2021-07-27 19:47:17+00:00

88.0b2 on Mac, delete of folder fails for my fastmail account.  Also in safe mode.
Delete of gmail folder succeeds.

Eric, are you using beta, and see this issue?

Prompter: internal dialogs not available in this context. Falling back to window prompt. Prompter.jsm:1033
    set modalType resource://gre/modules/Prompter.jsm:1033
    ModalPrompter resource://gre/modules/Prompter.jsm:989
    getPrompt resource://gre/modules/Prompter.jsm:65
    deleteFolder chrome://messenger/content/folderPane.js:3534
    oncommand chrome://messenger/content/messenger.xhtml:1
Bug: (profile) Problems after update - local files have also disappeared
Status: UNCONFIRMED
Priority: --
Created: 2021-04-07 13:41:08+00:00
Resolved: 2021-04-07 15:01:12+00:00

Vous m'avez forcé à mettre à jour Thunderbird.
Or, depuis j'ai constaté quelqueas anomalies :
- Les courriers entrants (2 comptes) ne sont plus unifiés, il faut les consulter un par un,
-l'agenda a été effacé, me causant un préjudice car je n'ai plus les travaux à réaliser, les anniverssaires, ...
-Les contacts sont invisibles (Voir copie écran),
-Les dossiers locaux ont également disparus ce qui est dommagable (perte d'informations)
Bug: Older messages not threaded
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-07 13:48:18+00:00
Resolved: 2021-11-06 15:01:36+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36

Steps to reproduce:

Due to previous problems with calendar sync and peculiar behaviour with the conversations add-on, I decided to make a new profile on a spare computer, then copy it over when ready. But the only thing stopping me from using the new profile is that not all my messages are being threaded. On the old profile they are fine. I've gone through all the "thread" related settings in the Config Editor and changed some to match but it made not difference. Any ideas as to what else I could experiment with?


Actual results:

New profile on "laptop" not threading messages prior to 05/03/2021, but old slightly damaged profile on "desktop" computer does thread the same messages.


Expected results:

All messages with matching subject should be threaded.
Bug: Unable to trigger an unfocused button in a MsgBox by pressing a single mnemonic/accelerator key (without holding Alt key)
Status: RESOLVED
Priority: --
Resolution: DUPLICATE
Created: 2021-04-07 18:09:57+00:00
Resolved: 2021-04-09 14:52:50+00:00

User Agent: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.91 Safari/537.36

Steps to reproduce:

Press N key to go to the next unread message in the list.

If there's none, it asks:
Advance to next unread message in (%S)?
Yes/No
(Y and N are underlined. [Yes] button is focused initially.)



Actual results:

To trigger [No] button, I have to:
use Alt+N;
or use Esc key;
or move the focus to [No] button, then press N key.



Expected results:

Before (v78?), I could trigger [No] button by pressing N key directly, which was the fastest way since my finger was still on N key.

In other apps, N (instead of Alt+N) can be used in such cases, when [&N] button is NOT focused, in a MsgBox.
Bug: Message uneditable (etc.) after IMAP save draft fails
Status: UNCONFIRMED
Priority: --
Created: 2021-04-08 01:16:16+00:00
Resolved: 2022-11-06 17:03:27+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

[version 78.9.0 (64-bit)]
1. Compose a message to be sent from an IMAP account
2. Disconnect from internet
3. Save message as draft
4. On "Copy failed." message, click Cancel (the only option)
(5. Re-connect to internet - optional)


Actual results:

1. Can no longer continue to edit message (all keystrokes seem to be ignored)
2. Save and Save As menu items are all greyed out
3. Send button is greyed out

The only workaround seems to be to copy and paste the content to a new message.


Expected results:

1. Should be able to continue editing message
2. Should be able to re-attempt save
3. Should be able to attempt to send message
Bug: Tags not working
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-08 04:54:59+00:00
Resolved: 2021-04-12 15:21:15+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

Pressing (eg) 4 in a mail to colour it (tagging) is not working in 78.9 version


Actual results:

No response


Expected results:

Mail link in the upper right window should be coloured according to the number pressed
Bug: 'Reply to all' behaviour is sub-optimal for some messages
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2021-04-08 12:01:19+00:00
Resolved: 2021-04-19 12:17:34+00:00

User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:86.0) Gecko/20100101 Firefox/86.0

Steps to reproduce:

I just clicked to 'Reply to all' on the attached message.



Actual results:

In my case, the Cc: list is moved to To: and the sender's (From:) e-mail is completely ignored.


Expected results:

I expect to reply to the sender (copy it to To:) and retain Cc: list as Cc: list in the composer.
Bug: Segmentation fault at start up - Error("Cannot load required OTR library", "resource:///modules/OTRLib.jsm", 75)
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2021-04-08 13:47:20+00:00
Resolved: 2024-03-02 19:46:55+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36

Steps to reproduce:

From command line:

thunderbird --safe-mode 


Actual results:

[calBackendLoader] Using Thunderbird's libical backend
console.debug: "Successfully loaded OpenPGP library librnp.so from /usr/lib/thunderbird/librnp.so"
console.debug: "public keys: 0, secret keys: 0"
console.debug: "Successfully loaded optional OpenPGP library libgpgme.so.11 from system's standard library locations"
console.debug: "gpgme version: 1.13.1-unknown"
console.log: (new Error("Cannot load required OTR library", "resource:///modules/OTRLib.jsm", 75))
Segmentation fault (core dumped)



Expected results:

Just start as usual.
Using: Thunderbird 78.7.1 20210203182138 20210203182138
Bug: Thunderbird 88.0b2 stops responding connected to an OpenExchange-Server
Status: RESOLVED
Priority: --
Resolution: INCOMPLETE
Created: 2021-04-08 14:19:19+00:00
Resolved: 2021-05-08 12:16:52+00:00

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.116 Safari/537.36

Steps to reproduce:

Install Thunderbird 88.0b2
Configure Thunderbird to connect to
- gmail.com
- OpenExchange
- Exchange via davmail


Actual results:

Thunderbird retrives all mail from all accounts, then stops. UI does not respond. Logging shows Thunderbird doing nothing, sitting there and consuming 100% CPU. Last logged entries:
[code]
[Parent 426875: IMAP]: I/IMAP 7f78918a8800:localhost:A:SendData: 5 list "" "INBOX"
[Parent 426875: IMAP]: D/IMAP ReadNextLine [rv=0x0 stream=7f78a23cd1f0 nb=37 needmore=0]
[Parent 426875: IMAP]: I/IMAP 7f78918a8800:localhost:A:CreateNewLineFromSocket: * list (\HasNoChildren) "/" "INBOX"
[Parent 426875: IMAP]: D/IMAP SetConnectionStatus(0x0)
[Parent 426875: IMAP]: D/IMAP ReadNextLine [rv=0x0 stream=7f78a23cd1f0 nb=21 needmore=0]
[Parent 426875: IMAP]: I/IMAP 7f78918a8800:localhost:A:CreateNewLineFromSocket: 5 OK list completed
[Parent 426875: IMAP]: D/IMAP SetConnectionStatus(0x0)
[/code]


Expected results:

Thunderbird retrieving all mail from all accounts, then being responsive allowing to work with these mail.
Bug: Problem with sending emails beetwen two mailboxes while replying
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2021-04-08 19:07:23+00:00
Resolved: 2021-04-24 08:01:25+00:00

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.114 Safari/537.36

Steps to reproduce:

I have two added accounts in my thunderbird
employee@aa.pl (my employee)
boss@bb.pl (mine)

When i receive mail from employee@aa.pl he is as a sender and i am as a recipient (boss@bb.pl).
BUT! When i press reply to this message, automatically thunderbird put employee@aa.pl in sender field and put me as a recipient (boss@bb.pl). But i should be a sender and employee should be a recipient. 

I tried to delete employee account from thunderbird and that's worked - all is like it should be. But i need to have an email of employee on my PC, so i added it back. And problem got back :)

Both e-mails are with different domains, but with the same server.

In outgoing mails settings i had two different profiles of SMTP (different title and different users) and i chose each as a default for each e-mail.

Dunno what more could i do.




Expected results:

When i press reply on message, the sender of this message should be in recipient field, not in sender field.
Bug: Message list & preview out-of-sync and locked up
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-08 19:22:57+00:00
Resolved: 2021-11-29 13:49:58+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

Bring TB window forward (environment Win10 64-bit). My layout is message list top right, preview pane bottom right. See screenshot. Clicked on the message with subject" Re: We have lost ...."

[This defect MAY BE related to bug 826426 or bug 1439644 but they are both old.]


Actual results:

Preview pane shows a totally different message with subject "Fwd: [allregions]..." Selecting a different messsage in list does NOTHING. No amount of clicking changes the displayed (previewed) message. I had to switch folders and then return to inbox, before the app un-froze.

Probably related to this is behavior for the last several months, where the message list is obviously stale but updates in about 10 secs when the app window is raised to the top of the stack. Before the app escapes its stupor, message list and preview are out of sync, but then repair themselves.


Expected results:

Preview pane and selected message in list should be synchronized 100% of the time.
Bug: Disappearance of Thunderbird Trash
Status: RESOLVED
Priority: --
Resolution: WORKSFORME
Created: 2021-04-08 19:56:23+00:00
Resolved: 2021-06-27 14:18:57+00:00

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:87.0) Gecko/20100101 Firefox/87.0

Steps to reproduce:

I am using at time thunderbird 68.10.0 64bit with Ubuntu 18.04. I experienced the disappearance of the trash folder in the Inbox.
I did an detailed analysis on the operating conditions of thunderbird with the following results:

a) When the trash folder is empty and thunderbird is stopped by closing the thunderbird-window or by system shutdown the trash folder keeps in place.
b) When the trash folder is not empty and thunderbird is stopped by closing the thunderbird-window the contents of the trash folder is deleted and the trash folder keeps in place.
c) When the trash folder is not empty and thunderbird is stopped by system shutdown the trash folder is deleted.

So it looks like the issue of the disappearance of the thunderbird trash folder is:
How thunderbird is stopped by system shutdown with a not empty trash folder!