Breaking Change: Remove deprecated FieldDescriptor::has_optional_keyword() in OSS. Use is_repeated() or has_presence() instead

https://protobuf.dev/news/2025-09-19/#cpp-remove-apis

PiperOrigin-RevId: 843293774

Author: anandolee

src/google/protobuf/descriptor.cc

@@ -3957,7 +3957,7 @@ void FieldDescriptor::DebugString(
 
   // Label is omitted for maps, oneof, and plain proto3 fields.
   if (is_map() || real_containing_oneof() ||
-      (!is_required() && !is_repeated() && !has_optional_keyword())) {
+      (!is_required() && !is_repeated() && !has_presence())) {
     label.clear();
   }
   // Label is omitted for optional and required fields under editions.
@@ -4279,12 +4279,6 @@ bool FieldDescriptor::legacy_enum_field_treated_as_closed() const {
           enum_type()->is_closed());
 }
 
-bool FieldDescriptor::has_optional_keyword() const {
-  return proto3_optional_ ||
-         (file()->edition() == Edition::EDITION_PROTO2 && !is_required() &&
-          !is_repeated() && !containing_oneof());
-}
-
 FieldDescriptor::CppStringType FieldDescriptor::CalculateCppStringType() const {
   ABSL_DCHECK(cpp_type() == FieldDescriptor::CPPTYPE_STRING);
 

src/google/protobuf/descriptor.h

@@ -1135,11 +1135,6 @@ class PROTOBUF_EXPORT FieldDescriptor : private internal::SymbolBase,
   int legacy_proto_ctype() const { return legacy_proto_ctype_; }
   bool has_legacy_proto_ctype() const;
 
-  // Returns true if this field was syntactically written with "optional" in the
-  // .proto file. Excludes singular proto3 fields that do not have a label.
-  ABSL_DEPRECATED("Use has_presence() instead.")
-  bool has_optional_keyword() const;
-
   // Get the merged features that apply to this field.  These are specified in
   // the .proto file through the feature options in the message definition.
   // Allowed features are defined by Features in descriptor.proto, along with