AltGr triggers email address selection from the contacts autocomplete suggestion list

[Mossroy]

I'm using Thunderbird 17.0.2 (17.0.2+build1-0ubuntu0.12.04.1) on Ubuntu 12.04.2 (with latest updates) with a French Keyboard, configured with default layout called "Français (variante)".

If I start composing a new message, and type some letters in the recipient address zone, Thunderbird suggests some email addresses from my contacts.
If I don't want to use one of these suggestions, I will have to type the @ symbol at some point.
On a French keyboard, the @ symbol can be obtained with AltGr key and "à" key : you have to press AltGr, then press à, and then release both keys.

The problem is that, as soon as you press AltGr, Thunderbird selects the first email address of his suggestions, and fills the recipient input field with it.
If you don't see it, you end up with a @ symbol at the end of the suggested email address.

The workarounds I found are :
- type quicker than Thunderbird suggests. If you're very fast, it can do the trick
- copy/paste the email address from somewhere else (or at least the @ symbol)

I have this same behavior on 2 different computers : one with Ubuntu x86 and, the other one with x64. Both under Unity 3D with Intel graphics card.
After some searching, I found an old bug on Thunderbird that triggered this exact issue : https://bugzilla.mozilla.org/show_bug.cgi?id=464914 . But it's been fixed in 2009.

It's very annoying because the @ symbol is mandatory in any email address...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mossroy (mossroy)]

I suspect this issue to be related to Unity3D.
If I reboot and choose another window manager (Unity2D or Gnome classic), the problem does not occur : alt gr does not select an address from the suggestions, and you can safely type the @ symbol.

Another strange behavior is that the problem disappears if I close the session, switch to another window manager, close the session again, and switch back to Unity3D.
It looks like the bug occurs only on Unity3D, and only if it's the first window manager after boot.

[Mossroy (mossroy)]

I still face this issue with Thunderbird 17.0.6 on Precise with latest updates

[Spott (spott-spottraining)]

I have the same problem. Estonian layout and latest stable Ubuntu 13.04

[Mossroy (mossroy)]

On Ubuntu 14.04 alpha (under Virtualbox), this issue does not seem to occur.
It would need to be checked in a real installation.
This is with Thunderbird 24.4.0. But the same Thunderbird version still has the issue under Ubuntu 12.04.4

[Simon P. (simpre)]

This bug is still annoying me on Ubuntu 15.10 with Thunderbird 38.4.0. German keyboard layout here, where the @ can be obtained by Alt Gr + q