[tahoe-dev] [tahoe-lafs] #956: embed security metadata in parent directory

[James A. Donald]

tahoe-lafs wrote:
 > #956: embed security metadata in parent directory
 >
 >  There is going to be a compatibility problem with doing this, since
 >  we don't (as far as I can see) have anywhere in the directory
 >  format to encode new fields that will be ignored by old clients.
 >  This will also be a problem with several other proposed features,
 >  including deep-verify caps as described in #308, and extensible
 >  directories suggested as part of #959.

The COM approach to addressing this type of problem is that the client
should never see the raw data of a structured object, rather a presentation
of that data, and the presentation depends on the negotiated interface, so
older clients see an older presentation.