Unchecked Return Value

Summary

The package `go-merkledag` implements the 'DAGService' interface and adds two ipld node types, Protobuf and Raw for the ipfs project. A `ProtoNode` may be modified in such a way as to cause various encode errors which will trigger a panic on common method calls that don't allow for error returns. A `ProtoNode` should only be able to encode to valid DAG-PB, attempting to encode invalid DAG-PB forms will result in an error from the codec. Manipulation of an existing (newly created or decoded) `ProtoNode` in versions 0.4.0 prior to 0.8.1 using the modifier methods did not account for certain states that would place the `ProtoNode` into an unencodeable form. Users unable to upgrade may attempt to mitigate this issue by sanitising inputs when allowing user-input to set a new `CidBuilder` on a `ProtoNode` and by sanitising `Tsize` (`Link#Size`) values such that they are a reasonable byte-size for sub-DAGs where derived from user-input.