[KUDU-1850] Check treatment of unknown values in protobuf repeated fields

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Not A Problem
• Affects Version/s: 1.2.0
• Fix Version/s: n/a
• Component/s: rpc
• Target Version/s: 1.3.0
• Assignee: Unassigned
• Reporter: Todd Lipcon
• Created: 25/Jan/17 23:58
• Updated: 26/Feb/17 23:33
• Resolved: 26/Feb/17 23:33

Description

We've been operating under the assumption that unknown values in 'repeated MyEnum foo' in protobuf would show up as the first variant of the enum. In fact this doesn't seem to be the case (at least in C++). Rather, the values end up in the UnknownFieldSet.

This might have impact in a few places, most notably the feature flags stuff in the RPC system.