comparison mercurial/changegroup.py @ 24190:903c7e8c97ad

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

24189:8b4b9ee6001a

        node = revlog.node(rev)
        p1, p2 = revlog.parentrevs(rev)
        base = self.deltaparent(revlog, rev, p1, p2, prev)

        prefix = ''
        if base == nullrev:
            delta = revlog.revision(node)
            prefix = mdiff.trivialdiffheader(len(delta))
        else:
            delta = revlog.revdiff(base, rev)
        p1n, p2n = revlog.parents(node)

24190:903c7e8c97ad

        node = revlog.node(rev)
        p1, p2 = revlog.parentrevs(rev)
        base = self.deltaparent(revlog, rev, p1, p2, prev)

        prefix = ''
        if revlog.iscensored(base) or revlog.iscensored(rev):
            try:
                delta = revlog.revision(node)
            except error.CensoredNodeError, e:
                delta = e.tombstone
            if base == nullrev:
                prefix = mdiff.trivialdiffheader(len(delta))
            else:
                baselen = revlog.rawsize(base)
                prefix = mdiff.replacediffheader(baselen, len(delta))
        elif base == nullrev:
            delta = revlog.revision(node)
            prefix = mdiff.trivialdiffheader(len(delta))
        else:
            delta = revlog.revdiff(base, rev)
        p1n, p2n = revlog.parents(node)