diff --git a/src/google/protobuf/sample_messages_edition.proto b/src/google/protobuf/sample_messages_edition.proto
new file mode 100644
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+++ b/src/google/protobuf/sample_messages_edition.proto
@@ -0,0 +1,427 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+//
+// Test schema for proto2 messages.  This test schema is used by:
+//
+// - conformance tests
+//
+
+edition = "2023";
+
+package protobuf_test_messages.edition;
+
+option optimize_for = SPEED;
+
+// This proto includes every type of field in both singular and repeated
+// forms.
+//
+// Also, crucially, all messages and enums in this file are eventually
+// submessages of this message.  So for example, a fuzz test of TestAllTypes
+// could trigger bugs that occur in any message type in this file.  We verify
+// this stays true in a unit test.
+message TestAllTypesEdition {
+  message NestedMessage {
+    int32 a = 1;
+    TestAllTypesEdition corecursive = 2;
+  }
+
+  enum NestedEnum {
+    FOO = 0;
+    BAR = 1;
+    BAZ = 2;
+    NEG = -1;  // Intentionally negative.
+  }
+
+  // Singular
+  int32 optional_int32 = 1;
+  int64 optional_int64 = 2;
+  uint32 optional_uint32 = 3;
+  uint64 optional_uint64 = 4;
+  sint32 optional_sint32 = 5;
+  sint64 optional_sint64 = 6;
+  fixed32 optional_fixed32 = 7;
+  fixed64 optional_fixed64 = 8;
+  sfixed32 optional_sfixed32 = 9;
+  sfixed64 optional_sfixed64 = 10;
+  float optional_float = 11;
+  double optional_double = 12;
+  bool optional_bool = 13;
+  string optional_string = 14;
+  bytes optional_bytes = 15;
+
+  NestedMessage optional_nested_message = 18;
+  ForeignMessageEdition optional_foreign_message = 19;
+
+  NestedEnum optional_nested_enum = 21;
+  ForeignEnumEdition optional_foreign_enum = 22;
+
+  string optional_string_piece = 24 [ctype = STRING_PIECE];
+  string optional_cord = 25 [ctype = CORD];
+
+  TestAllTypesEdition recursive_message = 27;
+
+  // Repeated
+  repeated int32 repeated_int32 = 31;
+  repeated int64 repeated_int64 = 32;
+  repeated uint32 repeated_uint32 = 33;
+  repeated uint64 repeated_uint64 = 34;
+  repeated sint32 repeated_sint32 = 35;
+  repeated sint64 repeated_sint64 = 36;
+  repeated fixed32 repeated_fixed32 = 37;
+  repeated fixed64 repeated_fixed64 = 38;
+  repeated sfixed32 repeated_sfixed32 = 39;
+  repeated sfixed64 repeated_sfixed64 = 40;
+  repeated float repeated_float = 41;
+  repeated double repeated_double = 42;
+  repeated bool repeated_bool = 43;
+  repeated string repeated_string = 44;
+  repeated bytes repeated_bytes = 45;
+
+  repeated NestedMessage repeated_nested_message = 48;
+  repeated ForeignMessageEdition repeated_foreign_message = 49;
+
+  repeated NestedEnum repeated_nested_enum = 51;
+  repeated ForeignEnumEdition repeated_foreign_enum = 52;
+
+  repeated string repeated_string_piece = 54 [ctype = STRING_PIECE];
+  repeated string repeated_cord = 55 [ctype = CORD];
+
+  // Packed
+  repeated int32 packed_int32 = 75 [features.repeated_field_encoding = PACKED];
+  repeated int64 packed_int64 = 76 [features.repeated_field_encoding = PACKED];
+  repeated uint32 packed_uint32 = 77
+      [features.repeated_field_encoding = PACKED];
+  repeated uint64 packed_uint64 = 78
+      [features.repeated_field_encoding = PACKED];
+  repeated sint32 packed_sint32 = 79
+      [features.repeated_field_encoding = PACKED];
+  repeated sint64 packed_sint64 = 80
+      [features.repeated_field_encoding = PACKED];
+  repeated fixed32 packed_fixed32 = 81
+      [features.repeated_field_encoding = PACKED];
+  repeated fixed64 packed_fixed64 = 82
+      [features.repeated_field_encoding = PACKED];
+  repeated sfixed32 packed_sfixed32 = 83
+      [features.repeated_field_encoding = PACKED];
+  repeated sfixed64 packed_sfixed64 = 84
+      [features.repeated_field_encoding = PACKED];
+  repeated float packed_float = 85 [features.repeated_field_encoding = PACKED];
+  repeated double packed_double = 86
+      [features.repeated_field_encoding = PACKED];
+  repeated bool packed_bool = 87 [features.repeated_field_encoding = PACKED];
+  repeated NestedEnum packed_nested_enum = 88
+      [features.repeated_field_encoding = PACKED];
+
+  // Unpacked
+  repeated int32 unpacked_int32 = 89
+      [features.repeated_field_encoding = EXPANDED];
+  repeated int64 unpacked_int64 = 90
+      [features.repeated_field_encoding = EXPANDED];
+  repeated uint32 unpacked_uint32 = 91
+      [features.repeated_field_encoding = EXPANDED];
+  repeated uint64 unpacked_uint64 = 92
+      [features.repeated_field_encoding = EXPANDED];
+  repeated sint32 unpacked_sint32 = 93
+      [features.repeated_field_encoding = EXPANDED];
+  repeated sint64 unpacked_sint64 = 94
+      [features.repeated_field_encoding = EXPANDED];
+  repeated fixed32 unpacked_fixed32 = 95
+      [features.repeated_field_encoding = EXPANDED];
+  repeated fixed64 unpacked_fixed64 = 96
+      [features.repeated_field_encoding = EXPANDED];
+  repeated sfixed32 unpacked_sfixed32 = 97
+      [features.repeated_field_encoding = EXPANDED];
+  repeated sfixed64 unpacked_sfixed64 = 98
+      [features.repeated_field_encoding = EXPANDED];
+  repeated float unpacked_float = 99
+      [features.repeated_field_encoding = EXPANDED];
+  repeated double unpacked_double = 100
+      [features.repeated_field_encoding = EXPANDED];
+  repeated bool unpacked_bool = 101
+      [features.repeated_field_encoding = EXPANDED];
+  repeated NestedEnum unpacked_nested_enum = 102
+      [features.repeated_field_encoding = EXPANDED];
+
+  // Map
+  map<int32, int32> map_int32_int32 = 56;
+  map<int64, int64> map_int64_int64 = 57;
+  map<uint32, uint32> map_uint32_uint32 = 58;
+  map<uint64, uint64> map_uint64_uint64 = 59;
+  map<sint32, sint32> map_sint32_sint32 = 60;
+  map<sint64, sint64> map_sint64_sint64 = 61;
+  map<fixed32, fixed32> map_fixed32_fixed32 = 62;
+  map<fixed64, fixed64> map_fixed64_fixed64 = 63;
+  map<sfixed32, sfixed32> map_sfixed32_sfixed32 = 64;
+  map<sfixed64, sfixed64> map_sfixed64_sfixed64 = 65;
+  map<int32, float> map_int32_float = 66;
+  map<int32, double> map_int32_double = 67;
+  map<bool, bool> map_bool_bool = 68;
+  map<string, string> map_string_string = 69;
+  map<string, bytes> map_string_bytes = 70;
+  map<string, NestedMessage> map_string_nested_message = 71;
+  map<string, ForeignMessageEdition> map_string_foreign_message = 72;
+  map<string, NestedEnum> map_string_nested_enum = 73;
+  map<string, ForeignEnumEdition> map_string_foreign_enum = 74;
+
+  oneof oneof_field {
+    uint32 oneof_uint32 = 111;
+    NestedMessage oneof_nested_message = 112;
+    string oneof_string = 113;
+    bytes oneof_bytes = 114;
+    bool oneof_bool = 115;
+    uint64 oneof_uint64 = 116;
+    float oneof_float = 117;
+    double oneof_double = 118;
+    NestedEnum oneof_enum = 119;
+  }
+
+  // extensions
+  extensions 120 to 200;
+
+  // groups
+  message Data {
+    int32 group_int32 = 202;
+    uint32 group_uint32 = 203;
+  }
+
+  Data data = 201 [features.message_encoding = DELIMITED];
+
+  // default values
+  int32 default_int32 = 241 [default = -123456789];
+  int64 default_int64 = 242 [default = -9123456789123456789];
+  uint32 default_uint32 = 243 [default = 2123456789];
+  uint64 default_uint64 = 244 [default = 10123456789123456789];
+  sint32 default_sint32 = 245 [default = -123456789];
+  sint64 default_sint64 = 246 [default = -9123456789123456789];
+  fixed32 default_fixed32 = 247 [default = 2123456789];
+  fixed64 default_fixed64 = 248 [default = 10123456789123456789];
+  sfixed32 default_sfixed32 = 249 [default = -123456789];
+  sfixed64 default_sfixed64 = 250 [default = -9123456789123456789];
+  float default_float = 251 [default = 9e9];
+  double default_double = 252 [default = 7e22];
+  bool default_bool = 253 [default = true];
+  string default_string = 254 [default = "Rosebud"];
+  bytes default_bytes = 255 [default = "joshua"];
+
+  // Test field-name-to-JSON-name convention.
+  // (protobuf says names can be any valid C/C++ identifier.)
+  int32 fieldname1 = 401;
+  int32 field_name2 = 402;
+  int32 _field_name3 = 403;
+  int32 field__name4_ = 404;
+  int32 field0name5 = 405;
+  int32 field_0_name6 = 406;
+  int32 fieldName7 = 407;
+  int32 FieldName8 = 408;
+  int32 field_Name9 = 409;
+  int32 Field_Name10 = 410;
+  int32 FIELD_NAME11 = 411;
+  int32 FIELD_name12 = 412;
+  int32 __field_name13 = 413;
+  int32 __Field_name14 = 414;
+  int32 field__name15 = 415;
+  int32 field__Name16 = 416;
+  int32 field_name17__ = 417;
+  int32 Field_name18__ = 418;
+
+  // Reserved for unknown fields test.
+  reserved 1000 to 9999;
+
+  // message_set test case.
+  message MessageSetCorrect {
+    option message_set_wire_format = true;
+
+    extensions 4 to max;
+  }
+
+  message MessageSetCorrectExtension1 {
+    extend MessageSetCorrect {
+      MessageSetCorrectExtension1 message_set_extension = 1547769;
+    }
+    string str = 25;
+  }
+
+  message MessageSetCorrectExtension2 {
+    extend MessageSetCorrect {
+      MessageSetCorrectExtension2 message_set_extension = 4135312;
+    }
+    int32 i = 9;
+  }
+}
+
+message ForeignMessageEdition {
+  int32 c = 1;
+}
+
+enum ForeignEnumEdition {
+  FOREIGN_FOO = 0;
+  FOREIGN_BAR = 1;
+  FOREIGN_BAZ = 2;
+}
+
+extend TestAllTypesEdition {
+  int32 extension_int32 = 120;
+}
+
+message UnknownToTestAllTypes {
+  int32 optional_int32 = 1001;
+  string optional_string = 1002;
+  ForeignMessageEdition nested_message = 1003;
+  message OptionalGroup {
+    int32 a = 1;
+  }
+  OptionalGroup optionalgroup = 1004 [features.message_encoding = DELIMITED];
+  bool optional_bool = 1006;
+  repeated int32 repeated_int32 = 1011;
+}
+
+message NullHypothesisEdition {}
+
+message EnumOnlyEdition {
+  enum Bool {
+    kFalse = 0;
+    kTrue = 1;
+  }
+}
+
+message OneStringEdition {
+  string data = 1;
+}
+
+message ProtoWithKeywords {
+  int32 inline = 1;
+  string concept = 2;
+  repeated string requires = 3;
+}
+
+message TestAllRequiredTypesEdition {
+  message NestedMessage {
+    int32 a = 1 [features.field_presence = LEGACY_REQUIRED];
+    TestAllRequiredTypesEdition corecursive = 2
+        [features.field_presence = LEGACY_REQUIRED];
+    TestAllRequiredTypesEdition optional_corecursive = 3;
+  }
+
+  enum NestedEnum {
+    FOO = 0;
+    BAR = 1;
+    BAZ = 2;
+    NEG = -1;  // Intentionally negative.
+  }
+
+  // Singular
+  int32 required_int32 = 1 [features.field_presence = LEGACY_REQUIRED];
+  int64 required_int64 = 2 [features.field_presence = LEGACY_REQUIRED];
+  uint32 required_uint32 = 3 [features.field_presence = LEGACY_REQUIRED];
+  uint64 required_uint64 = 4 [features.field_presence = LEGACY_REQUIRED];
+  sint32 required_sint32 = 5 [features.field_presence = LEGACY_REQUIRED];
+  sint64 required_sint64 = 6 [features.field_presence = LEGACY_REQUIRED];
+  fixed32 required_fixed32 = 7 [features.field_presence = LEGACY_REQUIRED];
+  fixed64 required_fixed64 = 8 [features.field_presence = LEGACY_REQUIRED];
+  sfixed32 required_sfixed32 = 9 [features.field_presence = LEGACY_REQUIRED];
+  sfixed64 required_sfixed64 = 10 [features.field_presence = LEGACY_REQUIRED];
+  float required_float = 11 [features.field_presence = LEGACY_REQUIRED];
+  double required_double = 12 [features.field_presence = LEGACY_REQUIRED];
+  bool required_bool = 13 [features.field_presence = LEGACY_REQUIRED];
+  string required_string = 14 [features.field_presence = LEGACY_REQUIRED];
+  bytes required_bytes = 15 [features.field_presence = LEGACY_REQUIRED];
+
+  NestedMessage required_nested_message = 18
+      [features.field_presence = LEGACY_REQUIRED];
+  ForeignMessageEdition required_foreign_message = 19
+      [features.field_presence = LEGACY_REQUIRED];
+
+  NestedEnum required_nested_enum = 21
+      [features.field_presence = LEGACY_REQUIRED];
+  ForeignEnumEdition required_foreign_enum = 22
+      [features.field_presence = LEGACY_REQUIRED];
+
+  string required_string_piece = 24
+      [ctype = STRING_PIECE, features.field_presence = LEGACY_REQUIRED];
+  string required_cord = 25
+      [ctype = CORD, features.field_presence = LEGACY_REQUIRED];
+
+  TestAllRequiredTypesEdition recursive_message = 27;
+  TestAllRequiredTypesEdition optional_recursive_message = 28;
+
+  // extensions
+  extensions 120 to 200;
+
+  // groups
+  message Data {
+    int32 group_int32 = 202 [features.field_presence = LEGACY_REQUIRED];
+    uint32 group_uint32 = 203 [features.field_presence = LEGACY_REQUIRED];
+  }
+
+  Data data = 201 [features.message_encoding = DELIMITED];
+
+  // default values
+  int32 default_int32 = 241
+      [default = -123456789, features.field_presence = LEGACY_REQUIRED];
+  int64 default_int64 = 242 [
+    default = -9123456789123456789,
+    features.field_presence = LEGACY_REQUIRED
+  ];
+  uint32 default_uint32 = 243
+      [default = 2123456789, features.field_presence = LEGACY_REQUIRED];
+  uint64 default_uint64 = 244 [
+    default = 10123456789123456789,
+    features.field_presence = LEGACY_REQUIRED
+  ];
+  sint32 default_sint32 = 245
+      [default = -123456789, features.field_presence = LEGACY_REQUIRED];
+  sint64 default_sint64 = 246 [
+    default = -9123456789123456789,
+    features.field_presence = LEGACY_REQUIRED
+  ];
+  fixed32 default_fixed32 = 247
+      [default = 2123456789, features.field_presence = LEGACY_REQUIRED];
+  fixed64 default_fixed64 = 248 [
+    default = 10123456789123456789,
+    features.field_presence = LEGACY_REQUIRED
+  ];
+  sfixed32 default_sfixed32 = 249
+      [default = -123456789, features.field_presence = LEGACY_REQUIRED];
+  sfixed64 default_sfixed64 = 250 [
+    default = -9123456789123456789,
+    features.field_presence = LEGACY_REQUIRED
+  ];
+  float default_float = 251
+      [default = 9e9, features.field_presence = LEGACY_REQUIRED];
+  double default_double = 252
+      [default = 7e22, features.field_presence = LEGACY_REQUIRED];
+  bool default_bool = 253
+      [default = true, features.field_presence = LEGACY_REQUIRED];
+  string default_string = 254
+      [default = "Rosebud", features.field_presence = LEGACY_REQUIRED];
+  bytes default_bytes = 255
+      [default = "joshua", features.field_presence = LEGACY_REQUIRED];
+
+  // Reserved for unknown fields test.
+  reserved 1000 to 9999;
+
+  // message_set test case.
+  message MessageSetCorrect {
+    option message_set_wire_format = true;
+
+    extensions 4 to max;
+  }
+
+  message MessageSetCorrectExtension1 {
+    extend MessageSetCorrect {
+      MessageSetCorrectExtension1 message_set_extension = 1547769;
+    }
+    string str = 25 [features.field_presence = LEGACY_REQUIRED];
+  }
+
+  message MessageSetCorrectExtension2 {
+    extend MessageSetCorrect {
+      MessageSetCorrectExtension2 message_set_extension = 4135312;
+    }
+    int32 i = 9 [features.field_presence = LEGACY_REQUIRED];
+  }
+}