Update

Author: odow

src/Utilities/product_of_sets.jl

@@ -255,13 +255,15 @@ Return the number of rows corresponding to a set of type `S`. That is, it is
 the sum of the dimensions of the sets of type `S`.
 """
 function num_rows(sets::OrderedProductOfSets, ::Type{S})::Int where {S}
-    @assert sets.final_touch
     i = set_index(sets, S)::Int
     rows = sets.rows[i]
     if isempty(rows)
         return 0
+    elseif sets.final_touch
+        return max(0, last(rows[end]) - first(rows[1]) + 1)
+    else
+        return mapreduce(length, +, rows)
     end
-    return max(0, last(rows[end]) - first(rows[1]) + 1)
 end
 
 function MOI.get(

test/Utilities/test_product_of_sets.jl

@@ -328,6 +328,9 @@ function test_zero_dimensional_function_mix_of_sets()
     MOI.Utilities.add_set(sets, i1, 1)
     MOI.Utilities.add_set(sets, i3)
     MOI.Utilities.add_set(sets, i1, 0)
+    @test MOI.Utilities.num_rows(sets, MOI.Nonpositives) == 3
+    @test MOI.Utilities.num_rows(sets, MOI.Nonnegatives) == 1
+    @test MOI.Utilities.num_rows(sets, MOI.EqualTo{Int}) == 1
     MOI.Utilities.final_touch(sets)
     # MOI.Nonpositives
     F, S = MOI.VectorAffineFunction{Int}, MOI.Nonpositives