fix: fix type-instability of get_root_indp

Author: AayushSabharwal

src/solutions/save_idxs.jl

@@ -44,12 +44,18 @@ function as_diffeq_array(vt::Vector{VectorTemplate}, t)
     return DiffEqArray(typeof(TupleOfArraysWrapper(vt))[], t, (1, 1))
 end
 
-function get_root_indp(indp)
-    if hasmethod(symbolic_container, Tuple{typeof(indp)}) &&
-       (sc = symbolic_container(indp)) !== indp
-        return get_root_indp(sc)
-    end
-    return indp
+function get_root_indp(prob::AbstractSciMLProblem)
+    prob.f.sys
+end
+
+function get_root_indp(prob::LinearProblem)
+    get_root_indp(prob.f)
+end
+
+get_root_indp(::Nothing) = nothing
+
+function get_root_indp(f::SymbolicLinearInterface)
+    get_root_indp(f.sys)
 end
 
 # Everything from this point on is public API