OCT error when define a single pane window

[JayHuLBL]

In class Buildings.HeatTransfer.Windows.BaseClasses.CenterOfGlass, when the number of glass layer nGlaLay is 1, there is no gas layer. So the Buildings.HeatTransfer.Windows.BaseClasses.GasConvection gas[nGlaLay-1] has size 0. In Dymola (version 2022), it will be seems as disabled instance. However, it would trigger error in OCT

Error at line 37, column 15, in file '/home/jianjun/GitFolder/modelica-buildings/Buildings/HeatTransfer/Windows/BaseClasses/CenterOfGlass.mo':
  Array size mismatch in modification of gas, expected size is [0] and size of binding expression is [1]

The parameter glaSys has type Buildings.HeatTransfer.Data.GlazingSystems.Generic, in which the vector gas in default has one element Buildings.HeatTransfer.Data.Gases.Air(x=-1).

Because of this setting, when we define a single pane window as

record Win670 =
    Buildings.HeatTransfer.Data.GlazingSystems.Generic (
    final glass={Buildings.ThermalZones.Detailed.Validation.BESTEST.Data.Glass600()},
    UFra=1.4) "Single pane, clear glass 3.048mm"

It will trigger the OCT error as above.

To Reproduce
Run model Buildings.ThermalZones.Detailed.Validation.BESTEST.Cases6xx.Case670 from branch issue3005_BEST_update (commit 423b95f) with the OCT. It should have error as above.

Possible solution
declare a parameter as

final parameter Boolean have_GasLay = nGlaLay > 1
    "True if it has gas layer";

and make the gas to be conditional:

  Buildings.HeatTransfer.Windows.BaseClasses.GasConvection gas[nGlaLay-1](
    each final A=A,
    final gas=glaSys.gas,
    each final til=til,
    each linearize=linearize,
    each final homotopyInitialization=homotopyInitialization) if have_GasLay
    "Window gas layer"
    annotation (Placement(transformation(extent={{20,10},{40,30}})));

[mwetter]

This is fixed on the master and maint_8.1.x branches