Unity-greeter mistakenly displays warning sign when you press Caps Lock that used for switching input language.

[Mikhail V. Golubev]

Caps Lock is used for switching input language (for switching between English and Russian keyboard language in my case).
But when you press Caps Lock in the logon screen (unity-greeter) the warning sign appears. This warning sign means that uppercase input mode (all capitals) is activated. But actually it's not activated in this case, because Caps Lock is used for switching input language.

Expected:
1. When you press Caps Lock keyboard switches to the next input language.
2. No warning signs appears.

What actually happens:
1. When you press Caps Lock keyboard switches to the next input language.
2. Warning sign (uppercase mode) appears.

Ubuntu 14.04 (amd64), unity-greeter 14.04.10-0ubuntu1