> ((frame-position 0 . 0) (frame-outer-size 598 . 1184) (external-border-size 1 . 1) (title-height . 0) (menu-bar-external) (menu-bar-size 0 . 0) (tool-bar-external) (tool-bar-position . top) (tool-bar-size 596 . 36) (frame-inner-size 596 . 1146))

These values are as expected too.

 > If I resize the frame, the mode line and echo area reappears.  If I just
 > split a window, the uppermost window gets a mode line, but there's still
 > no mode line or echo area in the bottom window.

I see.  Does the problem also appear when you turn the tool bar
initially off?  Do you use `desktop-save-mode'?  If any of these is
true, can you try the patch I proposed for Bug#19048 and which I attach
here again.

Thanks, martin