Allow Dichotomy to return solutions on error (#142)

Author: odow

src/algorithms/Dichotomy.jl

@@ -112,8 +112,7 @@ function optimize_multiobjective!(algorithm::Dichotomy, model::Optimizer)
         w = y_d[2] / (y_d[2] - y_d[1])
         status, solution = _solve_weighted_sum(model, algorithm, [w, 1.0 - w])
         if !_is_scalar_status_optimal(status)
-            # Exit the solve with some error.
-            return status, nothing
+            break # Exit the solve with some error.
         elseif solution ≈ solutions[a] || solution ≈ solutions[b]
             # We have found an existing solution. We're free to prune (a, b)
             # from the search space.

test/algorithms/Dichotomy.jl

@@ -434,6 +434,8 @@ function test_solve_failures()
         end
         MOI.optimize!(model)
         @test MOI.get(model, MOI.TerminationStatus()) == MOI.NUMERICAL_ERROR
+        @test MOI.get(model, MOI.ResultCount()) ==
+              (fail_after < 2 ? 0 : fail_after)
     end
     return
 end