changegroup: emit full-replacement deltas if either revision is censored To ensure that exchanged deltas in the presence of censored revisions can always be applied to the recipient repository, the deltas must replace the entire base text. To make this restriction reasonably enforceable, the delta must do so with a single patch operation. For background and broader design of the censorship feature, see: http://mercurial.selenic.com/wiki/CensorPlan