fix hcl:"field,unusedKeys" populate with extra keys from the AST

decoder.go

@@ -631,10 +631,19 @@ func (d *decoder) decodeStruct(name string, node ast.Node, result reflect.Value)
  }
  }
 
- usedKeys := make(map[string]struct{})
  decodedFields := make([]string, 0, len(fields))
  decodedFieldsVal := make([]reflect.Value, 0)
  unusedKeysVal := make([]reflect.Value, 0)
+
+ // fill unusedNodeKeys with keys from the AST
+ // a slice because we have to do equals case fold to match Filter
+ unusedNodeKeys := make([]string, 0)
+ for _, item := range list.Items {
+ for _, k := range item.Keys {
+ unusedNodeKeys = append(unusedNodeKeys, k.Token.Value().(string))
+ }
+ }
+
  for _, f := range fields {
  field, fieldValue := f.field, f.val
  if !fieldValue.IsValid() {
@@ -689,8 +698,8 @@ func (d *decoder) decodeStruct(name string, node ast.Node, result reflect.Value)
  continue
  }
 
- // Track the used key
- usedKeys[fieldName] = struct{}{}
+ // Track the used keys
+ unusedNodeKeys = removeCaseFold(unusedNodeKeys, fieldName)
 
  // Create the field name and decode. We range over the elements
  // because we actually want the value.
@@ -723,6 +732,14 @@ func (d *decoder) decodeStruct(name string, node ast.Node, result reflect.Value)
  }
  }
 
+ if len(unusedNodeKeys) > 0 {
+ // like decodedFields, populated the unusedKeys field(s)
+ sort.Strings(unusedNodeKeys)
+ for _, v := range unusedKeysVal {
+ v.Set(reflect.ValueOf(unusedNodeKeys))
+ }
+ }
+
  return nil
 }
 
@@ -734,3 +751,12 @@ func findNodeType() reflect.Type {
  value := reflect.ValueOf(nodeContainer).FieldByName("Node")
  return value.Type()
 }
+
+func removeCaseFold(xs []string, y string) []string {
+ for i, x := range xs {
+ if strings.EqualFold(x, y) {
+ return append(xs[:i], xs[i+1:]...)
+ }
+ }
+ return xs
+}