Fixes

src/Utilities/CleverDicts.jl

@@ -142,11 +142,11 @@ function Base.haskey(c::CleverDict{K}, key::K) where {K}
     return _is_dense(c) ? c.hash(key)::Int64 in c.set : haskey(c.dict, key)
 end
 
-function Base.keys(c::CleverDict)
+function Base.keys(c::CleverDict{K}) where {K}
     return if _is_dense(c)
-        map(c.inverse_hash, c.set)
+        [c.inverse_hash(K, index) for index in  c.set]
     else
-        keys(c.dict)
+        collect(keys(c.dict))
     end
 end
 

src/Utilities/model.jl

@@ -152,7 +152,11 @@ function MOI.is_valid(
     )
 end
 function MOI.is_valid(model::AbstractModel, ci::CI{F,S}) where {F,S}
-    return MOI.is_valid(constraints(model, ci), ci)
+    if MOI.supports_constraint(model, F, S)
+        return MOI.is_valid(constraints(model, ci), ci)
+    else
+        return false
+    end
 end
 function MOI.is_valid(model::AbstractModel, vi::VI)
     if model.variable_indices === nothing
@@ -626,9 +630,9 @@ end
 
 function MOI.get(model::AbstractModel, loc::MOI.ListOfConstraintIndices{F,S}) where {F,S}
     if MOI.supports_constraint(model, F, S)
-        return MOI.ConstraintIndex{F,S}[]
+        return MOI.get(constraints(model, F, S), loc)
     else
-        return MOI.get(constraints(model, loc), loc)
+        return MOI.ConstraintIndex{F,S}[]
     end
 end
 
@@ -640,8 +644,12 @@ function MOI.get(
     MOI.throw_if_not_valid(model, ci)
     return MOI.SingleVariable(MOI.VariableIndex(ci.value))
 end
-function MOI.get(model::AbstractModel, ::MOI.ConstraintFunction, ci::CI)
-    return _getfunction(model, ci, getconstrloc(model, ci))
+function MOI.get(
+    model::AbstractModel,
+    attr::Union{MOI.ConstraintFunction, MOI.ConstraintSet},
+    ci::MOI.ConstraintIndex
+)
+    return MOI.get(constraints(model, ci), attr, ci)
 end
 
 function _get_single_variable_set(
@@ -688,9 +696,6 @@ function MOI.get(
     MOI.throw_if_not_valid(model, ci)
     return _get_single_variable_set(model, S, ci.value)
 end
-function MOI.get(model::AbstractModel, ::MOI.ConstraintSet, ci::CI)
-    return _getset(model, ci, getconstrloc(model, ci))
-end
 
 function MOI.is_empty(model::AbstractModel)
     return isempty(model.name) &&

src/Utilities/vector_of_constraints.jl

@@ -31,7 +31,13 @@ function MOI.add_constraint(
     func::F,
     set::S
 ) where {F<:MOI.AbstractFunction,S<:MOI.AbstractSet}
-    return CleverDicts.add_item(v.constraints, (func, set))
+    # f needs to be copied, see #2
+    # We canonicalize the constraint so that solvers can avoid having to canonicalize
+    # it most of the time (they can check if they need to with `is_canonical`.
+    # Note that the canonicalization is not guaranteed if for instance
+    # `modify` is called and adds a new term.
+    # See https://github.com/jump-dev/MathOptInterface.jl/pull/1118
+    return CleverDicts.add_item(v.constraints, (canonical(func), copy(set)))
 end
 function MOI.is_valid(
     v::VectorOfConstraints{F,S},
@@ -44,11 +50,33 @@ function MOI.delete(v::VectorOfConstraints{F,S}, ci::MOI.ConstraintIndex{F,S}) w
     delete!(v.constraints, ci)
 end
 function MOI.get(v::VectorOfConstraints{F,S}, ::MOI.ConstraintFunction, ci::MOI.ConstraintIndex{F,S}) where {F,S}
+    MOI.throw_if_not_valid(v, ci)
     return v.constraints[ci][1]
 end
 function MOI.get(v::VectorOfConstraints{F,S}, ::MOI.ConstraintSet, ci::MOI.ConstraintIndex{F,S}) where {F,S}
+    MOI.throw_if_not_valid(v, ci)
     return v.constraints[ci][2]
 end
+function MOI.set(
+    v::VectorOfConstraints{F,S},
+    ::MOI.ConstraintFunction,
+    ci::MOI.ConstraintIndex{F,S},
+    func::F,
+) where {F,S}
+    MOI.throw_if_not_valid(v, ci)
+    v.constraints[ci] = (func, v.constraints[ci][2])
+    return
+end
+function MOI.set(
+    v::VectorOfConstraints{F,S},
+    ::MOI.ConstraintSet,
+    ci::MOI.ConstraintIndex{F,S},
+    set::S,
+) where {F,S}
+    MOI.throw_if_not_valid(v, ci)
+    v.constraints[ci] = (v.constraints[ci][1], set)
+    return
+end
 
 function MOI.get(
     v::VectorOfConstraints{F,S},
@@ -67,8 +95,8 @@ function MOI.modify(
     ci::MOI.ConstraintIndex{F,S},
     change::MOI.AbstractFunctionModification,
 ) where {F,S}
-    func, set = constraint[ci]
-    constraint[ci] = (modify_function(func, change), set)
+    func, set = v.constraints[ci]
+    v.constraints[ci] = (modify_function(func, change), set)
     return
 end