You would also have needed to have a slow unboundedly large data stream on the other end. I fuzzed a bunch of varint-using code last month and never found this,

You would also have needed to have a slow unboundedly large data stream on the other end. I fuzzed a bunch of varint-using code last month and never found this, because I was always working with in-memory buffers. The loop is simple enough that anything reasonably sized (e.g. under a GB) would probably not hit any reasonable timeout.