The bug

Entering the screen to add or edit a server on the multiplayer server list, two input boxes and several buttons appear. When clicking somewhere outside the input boxes and none of the buttons, the blinking cursor disappears. Then I pressed the TAB key and the cursor started blinking on both the name box and the address box at the same time and I could write in both boxes at the same time.

How to reproduce

1. Click the "Multiplayer" button in the main menu
2. Click "Add server" or select one previously added server and click "Edit server"
3. Click somewhere on the dirt background
4. Press the TAB key
5. Start writing

Note: This bug did not happen before any 1.6 release

Code analysis

Code analysis by bemoty can be found in this comment.