Open Radar

 
Summary:
With a FileVault enabled MacBook Pro, when this MacBook Pro is connected to an external Display via Mini Display Port -> Display Port, the unlock screen is not shown. Instead both Displays (the external and the internal) show a black screen. However Keyboard input is allowed in this time so that you are able to type your password and hit enter and it boots into OS X without any problems. You simply don’t see what you are doing.

Steps to Reproduce:
0. Ensure you have a FileVault enabled MacBook Pro.
1. Connect an external Display via mini Display Port to the MacBook Pro
2. Start the Mac

Expected Results:
The FileVault unlock screen is shown after a couple of seconds

Actual Results:
The FileVault unlock screen is never shown, the screen remains black. Yet you can enter your password after the expected number of seconds and hit enter and it will launch OS X as it would be expected when the screen would be visible.

Regression:


Notes:
This problem does not occur when pressing and holding the option key during launch and selecting the Macintosh HD. In that case both, the disk selection screen and the FileVault password screen are visible on screen as expected. This also does not happen when making a restart from OS X. In that case, the password unlock screen is also shown, though I don’t know if that is FileVault in that case?!

Please find attached a system report, that hopefully contains all required informations.