Comment 5 for bug 1286910

I can confirm this too.

I don't have the option "Allow different sources for each window" enable, but the bug still works. My setup is:
 - two keyboard layouts: English and Russian
 - Alt+LShift to change between layouts.
 - Use the same input source for all windows enabled.

I switch the layout to Russian, then lock the screen via Ctrl+Alt+L. Result: the lock screen keyboard layout is set to Russian instead of the default English layout.

An additional commend: the lock screen inherits the keyboard layout from the desktop, but the converse is not true: the layout of the desktop is the same as it was before the screen was locked, independently of whether it has been changed in the lock screen.

Linux stan-ThinkPad-T530 3.13.0-29-generic #53-Ubuntu SMP Wed Jun 4 21:00:20 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
gnome-screensaver 3.6.1-0ubuntu13 (trusty)