Issue 4218: Command line history doesn't reset when entering duplicate command

Steps to reproduce

  1. Open Firebug
  2. Enable and switch to the Console side panel
  3. Focus the Command Line
  4. Type 1 and press Enter
  5. Type 2 and press Enter
  6. Press Up
    2 should be shown inside the Command Line
  7. Press Enter
  8. Press Up
    2 should be shown inside the Command Line

Expected Results