fix: properly namespace array variables passed to subcomponents

Author: AayushSabharwal

src/ModelingToolkit.jl

@@ -72,7 +72,7 @@ import Symbolics: rename, get_variables!, _solve, hessian_sparsity,
                   ParallelForm, SerialForm, MultithreadedForm, build_function,
                   rhss, lhss, prettify_expr, gradient,
                   jacobian, hessian, derivative, sparsejacobian, sparsehessian,
-                  substituter, scalarize, getparent, hasderiv, hasdiff
+                  substituter, scalarize, getparent, hasderiv, hasdiff, Arr
 
 import DiffEqBase: @add_kwonly
 export independent_variables, unknowns, parameters, full_parameters, continuous_events,

src/systems/abstractsystem.jl

@@ -1112,6 +1112,7 @@ end
 
 apply_to_variables(f::F, ex) where {F} = _apply_to_variables(f, ex)
 apply_to_variables(f::F, ex::Num) where {F} = wrap(_apply_to_variables(f, unwrap(ex)))
+apply_to_variables(f::F, ex::Arr) where {F} = wrap(_apply_to_variables(f, unwrap(ex)))
 function _apply_to_variables(f::F, ex) where {F}
     if isvariable(ex)
         return f(ex)