internal/impl: weak field bugfixes
Fix a reversed error check in impl.Export{}.WeakNil.
Check to see if we have a type for the weak field on marshal/size.
Treat a typed nil valued in XXX_Weak as not indicating presence for
the field.
Change-Id: Id667ac7eb4f53236be9e181017082bd8cd21d115
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/198717
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/impl/weak.go b/internal/impl/weak.go
new file mode 100644
index 0000000..575c988
--- /dev/null
+++ b/internal/impl/weak.go
@@ -0,0 +1,46 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package impl
+
+import (
+ "reflect"
+
+ pref "google.golang.org/protobuf/reflect/protoreflect"
+)
+
+// weakFields adds methods to the exported WeakFields type for internal use.
+//
+// The exported type is an alias to an unnamed type, so methods can't be
+// defined directly on it.
+type weakFields WeakFields
+
+func (w *weakFields) get(num pref.FieldNumber) (_ pref.ProtoMessage, ok bool) {
+ if *w == nil {
+ return nil, false
+ }
+ m, ok := (*w)[int32(num)]
+ if !ok {
+ return nil, false
+ }
+ // As a legacy quirk, consider a typed nil to be unset.
+ //
+ // TODO: Consider fixing the generated set methods to clear the field
+ // when provided with a typed nil.
+ if v := reflect.ValueOf(m); v.Kind() == reflect.Ptr && v.IsNil() {
+ return nil, false
+ }
+ return Export{}.ProtoMessageV2Of(m), true
+}
+
+func (w *weakFields) set(num pref.FieldNumber, m pref.ProtoMessage) {
+ if *w == nil {
+ *w = make(weakFields)
+ }
+ (*w)[int32(num)] = Export{}.ProtoMessageV1Of(m)
+}
+
+func (w *weakFields) clear(num pref.FieldNumber) {
+ delete(*w, int32(num))
+}