fix saveat includes save_start for ARKODE

src/common_interface/solve.jl

@@ -483,8 +483,12 @@ function DiffEqBase.__init(prob::DiffEqBase.AbstractODEProblem{uType, tupType, i
     save_everystep = isempty(saveat), save_idxs = nothing,
     dense = save_everystep,
     save_on = true,
-    save_start = true,
-    save_end = true,
+    save_start = save_everystep || isempty(saveat) ||
+                     saveat isa Number ? true :
+                 prob.tspan[1] in saveat,
+    save_end = save_everystep || isempty(saveat) ||
+                   saveat isa Number ? true :
+               prob.tspan[2] in saveat,
     save_timeseries = nothing,
     progress = false,
     progress_steps = 1000,
@@ -1415,7 +1419,7 @@ function DiffEqBase.solve!(integrator::AbstractSundialsIntegrator; early_free =
             integrator.userfun.p = integrator.p
             solver_step(integrator, tstop)
             integrator.t = first(integrator.tout)
-            # NB: CVode, ARKode may warn and then recover if integrator.t == integrator.tprev so don't flag this as an error 
+            # NB: CVode, ARKode may warn and then recover if integrator.t == integrator.tprev so don't flag this as an error
             integrator.flag < 0 && break
             handle_callbacks!(integrator) # this also updates the interpolation
             integrator.flag < 0 && break