comparison mercurial/revlog.py @ 24120:a450e0a2ba0a

revlog: in addgroup, reject ill-formed deltas based on censored nodes

To ensure interoperability when clones disagree about which file nodes are
censored, a restriction is made on deltas based on censored nodes. Any such
delta must replace the full text of the base in a single patch.

If the recipient of a delta considers the base to be censored and the delta
is not in the expected form, the recipient must reject it, as it can't know
if the source has also censored the base.

For background and broader design of the censorship feature, see:
http://mercurial.selenic.com/wiki/CensorPlan

24119:a5a06c9c7407

                if deltabase not in self.nodemap:
                    raise LookupError(deltabase, self.indexfile,
                                      _('unknown delta base'))

                baserev = self.rev(deltabase)
                chain = self._addrevision(node, None, transaction, link,
                                          p1, p2, REVIDX_DEFAULT_FLAGS,
                                          (baserev, delta), ifh, dfh)
                if not dfh and not self._inline:
                    # addrevision switched from inline to conventional

24120:a450e0a2ba0a

                if deltabase not in self.nodemap:
                    raise LookupError(deltabase, self.indexfile,
                                      _('unknown delta base'))

                baserev = self.rev(deltabase)

                if baserev != nullrev and self.iscensored(baserev):
                    # if base is censored, delta must be full replacement in a
                    # single patch operation
                    hlen = struct.calcsize(">lll")
                    oldlen = self.rawsize(baserev)
                    newlen = len(delta) - hlen
                    if delta[:hlen] != mdiff.replacediffheader(oldlen, newlen):
                        raise error.CensoredBaseError(self.indexfile,
                                                      self.node(baserev))

                chain = self._addrevision(node, None, transaction, link,
                                          p1, p2, REVIDX_DEFAULT_FLAGS,
                                          (baserev, delta), ifh, dfh)
                if not dfh and not self._inline:
                    # addrevision switched from inline to conventional