I don't see a problem with deleting things with any existing gmail accounts in a couple profiles. I also created a new gmail account in an existing profile and it also works fine and deletes to the inner [Gmail]/Trash. This is with a recent trunk build.
I have the outer Trash folder (not under [Gmail]) that I'm pretty sure I created while experimenting with gmail trash behavior. Those can be deleted optionally. I've also read that the outer Trash may be created by other clients accessing the gmail account and that the actual label name at gmail is [Imap]/Trash. I also found that [Imap]/Trash might have a special ability to "immediately" deleted anything placed into it almost like a black hole, but that may be an urban legend, and it just seems to behave for me like any other user created folder.
Also, I should mention that on my gmail accounts I don't have the mail.server.serverX.trash_folder_name in prefs.js for any of them and the delete to [Gmail]/Trash works fine.
But curious why Jonathan's gmail failed to completely delete before he tweaked it.
(In reply to Jorg K (GMT+2) from comment #7)
So I opened one of them and looked at my prefs. mail.server.server11.trash_folder_name was set to [Gmail]/Trash. So I reset it.
Jorg, do you mean you "reset" it in config editor? When I reset it (or if I just remove the line from prefs.js) I see "Choose Folder" in server setting for the trash destination.
I deleted a bunch of test e-mails from "All Mail" and they all went to the Trash and didn't bounce back. BTW, can someone explain to me what "All Mail" is? I thought it was a collection of all mail from all other folders, but it had some mail not seen in any other folder.
I restarted TB, and the pref came back. Most likely TB talks to the Gmail IMAP folder and asks about the folders and stores the pref for the trash folder. That happens here during discovery:
I don't see it come back in the prefs.js or in the config editor. But the [Gmail]/Trash still works.
Summary: With or without the pref set (which gets set on every start unless I'm missing something) I can't reproduce the issue.
I don't see a problem either but there are probably variations that we could be missing, e.g., whatever Jonathan saw.
None of my top level Trash folders had the trash icon like Jonathan saw. However, the new feature allows a user to select them as the trash destination if wanted (or any other user created folder).
Ok, I can see this as a possible problem: A user with pre-70b had selected a not [Gmail]/Trash folder as the trash destination. This really doesn't work and [Gmail]/Trash remains the destination even though the other folder is configured. Then when a 70b user runs TB with this setup, the not [Gmail]/Trash folder becomes the trash destination. Jonathan saw something like this when the "outer" Trash had the trash icon (but he says it was never configured as such). So in this case the user needs to "reset" the trash_folder_name setting or explicitly set the trash folder setting to [Gmail]/Trash in server settings to ensure that the default [Gmail]/Trash remains the trash destination.
Something about this should be in the release notes.