"Extend" can also extend groups

Use case:

// test.proto
syntax = "proto2";
package google.proto.test;

message TopMessage {
  message MidMessage {
    message BottomMessage {
      extensions 4 to max;
    }

    optional group BottomGroup = 1 {
      extensions 4 to max;
    }
  }

  optional group MidGroup = 2 {
    message BottomMessage {
      extensions 4 to max;
    }

    optional group BottomGroup = 3 {
      extensions 4 to max;
    }
  }
}

// test2.proto

syntax = "proto2";

import "test.proto";

extend .google.proto.test.TopMessage.MidMessage.BottomMessage {
  optional int32 v2_message_message_ext = 1;
}

extend .google.proto.test.TopMessage.MidMessage.BottomGroup {
  optional int32 v2_message_group_ext = 2;
}

extend .google.proto.test.TopMessage.MidGroup.BottomMessage {
  optional int32 v2_group_message_ext = 3;
}

extend .google.proto.test.TopMessage.MidGroup.BottomGroup {
  optional int32 v2_group_group_ext = 4;
}

Original issue reported on code.google.com by alr...@google.com on 29 Nov 2011 at 4:05

spearway / protobuf-dt

"Extend" can also extend groups #169