Update the displayed text when closing a combobox with the keyboard causes a new option to be selected. Bug 257572, r=mkaply, sr=jst.

layout/forms/nsListControlFrame.cpp

@@ -3049,6 +3049,7 @@ nsListControlFrame::DropDownToggleKey(nsIDOMEvent* aKeyEvent)
     PRBool isDroppedDown;
     mComboboxFrame->IsDroppedDown(&isDroppedDown);
     mComboboxFrame->ShowDropDown(!isDroppedDown);
+    mComboboxFrame->RedisplaySelectedText();
     aKeyEvent->PreventDefault();
   }
 }

layout/html/forms/src/nsListControlFrame.cpp

@@ -3049,6 +3049,7 @@ nsListControlFrame::DropDownToggleKey(nsIDOMEvent* aKeyEvent)
     PRBool isDroppedDown;
     mComboboxFrame->IsDroppedDown(&isDroppedDown);
     mComboboxFrame->ShowDropDown(!isDroppedDown);
+    mComboboxFrame->RedisplaySelectedText();
     aKeyEvent->PreventDefault();
   }
 }