mouse documentation line during nested DW:TRACKING-MOUSE

[Qobi@ZERMATT.LCS.MIT.EDU (Jeffrey Mark Siskind)]

Consider the following use of a nested DW:TRACKING-MOUSE

(dw:tracking-mouse (t :who-line-documentation-string "Foo")
 (:mouse-click (click x y)
  (dw:tracking-mouse (t :who-line-documentation-string "Bar")
   (:release-mouse () (return)))))

When the outer call is first executing, "Foo" correctly appears
in the mouse documentation line. When you click and thus enter the
inner call, "Bar" correctly appears. But when you release the click,
"Bar" disappears but "Foo" does not reappear. In fact, the mouse
documentation line remains blank. Is this a bug or am I doing
something wrong? What should I do to get "Foo" to reappear?

Second question:

How can I get the mouse documentation line in a DW:TRACKING-MOUSE
to switch depending on the state of the control-, meta-, etc. keys.
(I want to build the standard mouse documentation line inside
DW:TRACKING-MOUSE, i.e.

Mouse-L: Foo; Mouse-M: Bar; Mouse-R: Baz.
To see other commands, press Shift, Control, Meta-Shift, or Super.)
        Thanks,
        Jeff