In the console versions of Portal 2, the co-op pause menu has some changes made while playing in splitscreen: the "your partner in science" card is removed, and the exit to main menu prompt is changed to no longer state that your partner will be disconnected. Screenshots from PS3 version:
In the PC/Mac/Linux version, this does not work; when playing in splitscreen, the "your partner in science" card is still shown (with a default placeholder icon and no name), and the exit to main menu prompt still states that your partner will be disconnected.
Looking in ingamemainmenu_mp.res, the splitscreen layout is properly set up to appear when the ?online condition evaluates to false, so it appears that this is incorrectly always getting set to true even when not playing online co-op.
In the console versions of Portal 2, the co-op pause menu has some changes made while playing in splitscreen: the "your partner in science" card is removed, and the exit to main menu prompt is changed to no longer state that your partner will be disconnected. Screenshots from PS3 version:
In the PC/Mac/Linux version, this does not work; when playing in splitscreen, the "your partner in science" card is still shown (with a default placeholder icon and no name), and the exit to main menu prompt still states that your partner will be disconnected.
Looking in
ingamemainmenu_mp.res, the splitscreen layout is properly set up to appear when the?onlinecondition evaluates to false, so it appears that this is incorrectly always getting set to true even when not playing online co-op.