Fix switching among buildmenu and gridmenu. (#3961)

* Fix switching among buildmenu and gridmenu.

* Comment so hopefully this won't happen again.

* Fix typo in comment.

luaui/Widgets/gui_buildmenu.lua

@@ -1246,7 +1246,9 @@ end
 
 function widget:Initialize()
 	if widgetHandler:IsWidgetKnown("Grid menu") then
-		widgetHandler:DisableWidget("Grid menu")
+		-- Grid menu needs to be disabled right now and before we recreate
+		-- WG['buildmenu'] since its Shutdown will destroy it.
+		widgetHandler:DisableWidgetRaw("Grid menu")
 	end
 
 	units.checkGeothermalFeatures()

luaui/Widgets/gui_gridmenu.lua

@@ -1239,6 +1239,12 @@ local function cycleBuilder()
 end
 
 function widget:Initialize()
+	if widgetHandler:IsWidgetKnown("Build menu") then
+		-- Build menu needs to be disabled right now and before we recreate
+		-- WG['buildmenu'] since its Shutdown will destroy it.
+		widgetHandler:DisableWidgetRaw("Build menu")
+	end
+
 	myTeamID = Spring.GetMyTeamID()
 	isSpec = Spring.GetSpectatingState()
 	isPregame = Spring.GetGameFrame() == 0 and not isSpec
@@ -1248,10 +1254,6 @@ function widget:Initialize()
 
 	doUpdateClock = os.clock()
 
-	if widgetHandler:IsWidgetKnown("Build menu") then
-		widgetHandler:DisableWidget("Build menu")
-	end
-
 	units.checkGeothermalFeatures()
 
 	widgetHandler.actionHandler:AddAction(self, "gridmenu_key", gridmenuKeyHandler, nil, "pR")