Merge pull request #67 from SciML/dtmax_error

Insert a safety error for lack of fixed point iteration

Author: ChrisRackauckas

src/solve.jl

@@ -513,6 +513,10 @@ function DiffEqBase.solve!(integrator::SDDEIntegrator)
             if DiffEqBase.check_error!(integrator) != ReturnCode.Success
                 return integrator.sol
             end
+            if integrator.dt > minimum(integrator.sol.prob.constant_lags) &&
+               !(integrator.alg <: StochasticDiffEq.EM)
+                error("dt > minimum(constant_lags). This is not allowed by the integrator. Please dt `dtmax` less than the minimum lag or use `EM`.")
+            end
             StochasticDiffEq.perform_step!(integrator, integrator.cache)
             loopfooter!(integrator)
             if isempty(integrator.opts.tstops)