gtkairo crash: tab layout and input focus

[David Lichteblau]

To reproduce, just open the tab layout demo, then close it.

(This used to work.)

debugger invoked on a SIMPLE-ERROR in thread #<THREAD "initial thread" {1002396\
221}>:
  There is no applicable method for the generic function
    #<STANDARD-GENERIC-FUNCTION CLIM:STREAM-SET-INPUT-FOCUS (2)>
  when called with arguments
    (#<CLIM:VRACK-PANE "(Unnamed Pane)" {10035AF3A1}>).

restarts (invokable by number or by possibly-abbreviated name):
  0: [ABORT] Return to application command loop
  1:         Exit debugger, returning to top level.

((SB-PCL::FAST-METHOD NO-APPLICABLE-METHOD (T))
 #<unused argument>
 #<unused argument>
 #<STANDARD-GENERIC-FUNCTION CLIM:STREAM-SET-INPUT-FOCUS (2)>
 #<CLIM:VRACK-PANE "(Unnamed Pane)" {10035AF3A1}>)
0]