protoc sets extension range max to 2147483647 instead of 536870912 when message_set_wire_format = true

[protobufel]

Scenario:

1. use protoc (tested on Windows) to produce FileDescriptorSet file out of

test1.proto:

message Message1 {
extensions 1 to max;
}

1. roughly as below:
   FileDescriptorProto proto = ProtoFileDescriptorSet.parseFrom(..."test1.proto"...).get(0);
   proto.getMessageType(0).getExtensionRange().getEnd() == 2147483647 instead of 536870912

There is possibility that this is the Java ProtoFileDescriptorSet.parseFrom() bug, though.I didn't have time to check.

Cheers,
David

[xfxyjwf]

The problem may be one of the two:

1. the FileDescriptorSet file contains 2147483647 instead of 536870912. This indicates a bug in protoc.
2. FileDescriptorSet.parseFrom() magically turns 536870912 to 2147483647. This is very unlikely because FileDescriptorSet is just a normal protobuf message.

I couldn't reproduce either of these. Can you double check?

[protobufel]

Here is the problem:

message MessageMaxRange1 {
option message_set_wire_format = true;
extensions 1 to max;
}

Without message_set_wire_format everything's fine!

This is a protoc bug!... or Java's :) your turn!

Regards,
David

[xfxyjwf]

Why do you use message_set_wire_format? It's not a feature we support in open-source protobuf.

[protobufel]

I don't! What I am saying that protoc output is erroneous; could possibly used for malicious purposes and such. I am not suggesting that it's a security breach, but it is a bug.

[xfxyjwf]

It's not a bug. When message_set_wire_format is enabled, the extension range is supposed to be up to 2147483647. This is an internal only feature. It spreads too widely across the code base so we haven't been able remove it from open-source release.