Fix bug handling Adjoints in macros

src/parse_expr.jl

@@ -285,6 +285,12 @@ function destructive_add!(ex::AbstractArray{<:GenericAffExpr}, c::Number,
     return result
 end
 
+# For cases such as x' * x, broadcasting the ex .+ will cause the Adjoint to be
+# collected into an Array{T, 2}. The easiest way to work around this is to undo
+# the adjoint, perform the operation, and then re-apply the adjoint.
+function destructive_add!(ex::Number, c::Number, x::Adjoint{T, Vector{T}}) where {T}
+    return (ex .+ c * x')'
+end
 
 destructive_add!(ex, c, x) = ex .+ c * x
 

test/macros.jl

@@ -270,6 +270,17 @@ end
             "DenseAxisArray, or SparseAxisArray.")
         @test_throws exception @variable(model, x[1:3], container=Oops)
     end
+
+    @testset "Adjoints" begin
+        model = Model()
+        @variable(model, x[1:2])
+        obj = @objective(model, Min, x' * x)
+        @test obj == sum(x.^2)
+        cref = @constraint(model, x' * x <= 1)
+        c = JuMP.constraint_object(cref)
+        @test JuMP.isequal_canonical(c.func, sum(x.^2))
+        @test c.set == MOI.LessThan(1.0)
+    end
 end
 
 @testset "Macros for JuMPExtension.MyModel" begin