Reset the indices in the PresetTimeCallback

Fixes SciML/DifferentialEquations.jl#1022

src/preset_time.jl

@@ -56,6 +56,12 @@ function PresetTimeCallback(tstops, user_affect!;
     # Initialization: first call to `f` should be *before* any time steps have been taken:
     initialize_preset = function (c, u, t, integrator)
         initialize(c, u, t, integrator)
+        if tstops isa AbstractVector
+            search_start, search_end = firstindex(tstops), lastindex(tstops)
+        else
+            search_start, search_end = 0, 0
+        end
+
         if filter_tstops
             tdir = integrator.tdir
             _tstops = tstops[@.((tdir * tstops >

test/preset_time.jl

@@ -56,3 +56,33 @@ cb = PresetTimeCallback([-0.2], integrator -> begin
     end, filter_tstops = false)
 sol = solve(prob, Tsit5(), callback = cb)
 @test !notcalled
+
+# Test indexes reset
+# https://github.com/SciML/DifferentialEquations.jl/issues/1022
+
+function mod(du, u, p, t)
+    du[1] = -p[1]*u[1]
+end
+
+p = [1.0]
+u0 = [10.0]
+tspan = (0.0,72.0)
+
+times1 = 0.0:24.0:tspan[2]
+times2 = 24.0:24.0:tspan[2]
+affect!(integrator) = integrator.u[1] += 10.0
+cb1 = PresetTimeCallback(times1, affect!)
+cb2 = PresetTimeCallback(times2, affect!)
+
+prob1 = ODEProblem(mod, u0, tspan, p, callback=cb1)
+prob2 = ODEProblem(mod, u0, tspan, p)
+
+sol1 = solve(prob1)
+sol2 = solve(prob2, callback=cb1)
+
+@test sol1(0.0) == [10.0]
+@test sol1(24.0 + eps(24.0)) ≈ [10.0]
+@test sol1(48.0 + eps(48.0)) ≈ [10.0]
+@test sol2(0.0) == [10.0]
+@test sol2(24.0 + eps(24.0)) ≈ [10.0]
+@test sol2(48.0 + eps(48.0)) ≈ [10.0]