Padding the initial condition fails

[ChrisRackauckas]

ode_prob = ODEProblem((t,u)->u''+(c+1)*u',u0,(0.,1.))
prob = ApproxFunProblem(ode_prob)
@time sol=solve(prob,Tsit5())

is fine, but

ode_prob = ODEProblem((t,u)->u''+(c+1)*u',u0,(0.,1.))
prob = ApproxFunProblem(ode_prob,40)
@time sol=solve(prob,Tsit5())

fails. Notice that

function ApproxFunProblem(prob;n = ncoefficients(prob.u0))
  sp = space(prob.u0)
  _prob = ODEProblem((t,u)->pad!(prob.f(t,Fun(sp,u)).coefficients,n),pad!(prob.u0.coefficients,n),prob.tspan)
  return ApproxFunProblem(_prob,sp)
end

this is just padding u0, so I'm not sure why this would make such a huge difference if it's increased.

@dlfivefifty ?

[dlfivefifty]

What do you mean by "fails"? (Busy at the moment so can't try it out.)

[dlfivefifty]

Also, I'd need to see u0 to test it out

[ChrisRackauckas]

S=Fourier()
u0=Fun(θ->cos(cos(θ-0.1))-cos(cos(0-0.1)),S)
c=Fun(cos,S)

The first step grows to 100,000 terms and then it warns and exits.