Fix copy_to with empty constraint rows (#228)

Project.toml

@@ -1,7 +1,7 @@
 name = "GLPK"
 uuid = "60bf3e95-4087-53dc-ae20-288a0d20c6a6"
 repo = "https://github.com/jump-dev/GLPK.jl.git"
-version = "1.1.2"
+version = "1.1.3"
 
 [deps]
 GLPK_jll = "e8aa6df9-e6ca-548a-97ff-1f85fc5b8b98"

src/MOI_wrapper/MOI_copy.jl

@@ -124,7 +124,7 @@ function _extract_row_data(src, map, cache, ::Type{S}) where {S}
     F = MOI.ScalarAffineFunction{Float64}
     ci_map = map.con_map[F, S]
     nnz = length(cache.I)
-    row = nnz == 0 ? 1 : cache.I[end] + 1
+    row = length(cache.rl) + 1
     for ci in MOI.get(src, MOI.ListOfConstraintIndices{F,S}())
         f = MOI.get(src, MOI.ConstraintFunction(), ci)
         if !MOI.Utilities.is_canonical(f)

test/MOI_wrapper.jl

@@ -629,6 +629,28 @@ function test_attribute_TimeLimitSec()
     return
 end
 
+function test_copy_to_bug_HiGHS_172()
+    model = MOI.Utilities.Model{Float64}()
+    x = MOI.add_variable(model)
+    F = MOI.ScalarAffineFunction{Float64}
+    c1 = MOI.add_constraint(model, 2.0 * x, MOI.GreaterThan(0.0))
+    c2 = MOI.add_constraint(model, zero(F), MOI.GreaterThan(0.0))
+    c3 = MOI.add_constraint(model, 1.0 * x, MOI.EqualTo(1.0))
+    h = GLPK.Optimizer()
+    MOI.set(h, MOI.Silent(), true)
+    index_map = MOI.copy_to(h, model)
+    y = index_map[x]
+    @test MOI.get(h, MOI.ConstraintFunction(), index_map[c1]) ≈ 2.0 * y
+    @test MOI.get(h, MOI.ConstraintFunction(), index_map[c2]) ≈ zero(F)
+    @test MOI.get(h, MOI.ConstraintFunction(), index_map[c3]) ≈ 1.0 * y
+    @test MOI.get(h, MOI.ConstraintSet(), index_map[c1]) == MOI.GreaterThan(0.0)
+    @test MOI.get(h, MOI.ConstraintSet(), index_map[c2]) == MOI.GreaterThan(0.0)
+    @test MOI.get(h, MOI.ConstraintSet(), index_map[c3]) == MOI.EqualTo(1.0)
+    MOI.optimize!(h)
+    @test MOI.get(h, MOI.TerminationStatus()) == MOI.OPTIMAL
+    return
+end
+
 end  # module
 
 TestMOIWrapper.runtests()