helper/schema: validate Set is a set type [GH-413]

CHANGELOG.md

@@ -9,6 +9,7 @@ BUG FIXES:
       computed so the value is still unknown.
   * core: If a resource fails to create and has provisioners, it is
       marked as tainted. [GH-434]
+  * core: Set types are validated to be sets. [GH-413]
   * providers/aws: Refresh of launch configs and autoscale groups load
       the correct data and don't incorrectly recreate themselves. [GH-425]
   * providers/aws: Fix case where ELB would incorrectly plan to modify

helper/schema/schema.go

@@ -819,6 +819,8 @@ func (m schemaMap) validatePrimitive(
 	}
 
 	switch schema.Type {
+	case TypeSet:
+		fallthrough
 	case TypeList:
 		return m.validateList(k, raw, schema, c)
 	case TypeInt:

helper/schema/schema_test.go

@@ -1970,6 +1970,26 @@ func TestSchemaMap_Validate(t *testing.T) {
 
 			Err: true,
 		},
+
+		// Not a set
+		{
+			Schema: map[string]*Schema{
+				"ports": &Schema{
+					Type:     TypeSet,
+					Required: true,
+					Elem:     &Schema{Type: TypeInt},
+					Set: func(a interface{}) int {
+						return a.(int)
+					},
+				},
+			},
+
+			Config: map[string]interface{}{
+				"ports": "foo",
+			},
+
+			Err: true,
+		},
 	}
 
 	for i, tc := range cases {