Cannot call `to_index(::RaggedEnd)`

[vyudu]

Describe the bug 🐞

This threw for me when trying to symbolically index a solution using sol[:x, end] which used to work. sol[:x][end] does work, but I wanted to flag this in case.

Expected behavior

Should return the last value instead of erroring.

Minimal Reproducible Example 👇

using ModelingToolkit: t_nounits as t, D_nounits as D
using OrdinaryDiffEqTsit5
@variables x(t)
@named sys = System([D(x) ~ 1], t)
prob = ODEProblem(complete(sys), [x => 1], (0, 1))
sol = solve(prob, Tsit5())
sol[x, end]

Error & Stacktrace ⚠️

ERROR: ArgumentError: invalid index: RaggedEnd(0, 2) of type RaggedEnd
Stacktrace:
  [1] to_index(i::RaggedEnd)
    @ Base ./indices.jl:315
  [2] to_index(A::Vector{Vector{Float64}}, i::RaggedEnd)
    @ Base ./indices.jl:292
  [3] to_indices
    @ ./indices.jl:368 [inlined]
  [4] to_indices
    @ ./indices.jl:360 [inlined]
  [5] getindex
    @ ./abstractarray.jl:1342 [inlined]
  [6] state_values(sol::ODESolution{…}, i::RaggedEnd)
    @ SciMLBase ~/.julia/packages/SciMLBase/hHrRi/src/solutions/solution_interface.jl:83
  [7] (::SymbolicIndexingInterface.GetStateIndex{…})(::SymbolicIndexingInterface.Timeseries, prob::ODESolution{…}, i::RaggedEnd)
    @ SymbolicIndexingInterface ~/.julia/packages/SymbolicIndexingInterface/D9aQf/src/state_indexing.jl:44
  [8] (::SymbolicIndexingInterface.GetStateIndex{…})(prob::ODESolution{…}, i::RaggedEnd)
    @ SymbolicIndexingInterface ~/.julia/packages/SymbolicIndexingInterface/D9aQf/src/value_provider_interface.jl:167
  [9] _getindex
    @ ~/.julia/packages/RecursiveArrayTools/cqMRn/src/vector_of_array.jl:476 [inlined]
 [10] getindex(A::ODESolution{…}, _arg::Symbol, args::RaggedEnd)
    @ RecursiveArrayTools ~/.julia/packages/RecursiveArrayTools/2UpjF/src/vector_of_array.jl:750
 [11] top-level scope
    @ REPL[39]:1

Additional context

Add any other context about the problem here.

[JoshuaLampert]

Thanks for the report. Should be fixed by #516.