On Mon, Feb 6, 2012 at 1:28 PM, Greg Stein <gst...@gmail.com> wrote: > On Mon, Feb 6, 2012 at 12:48, <hwri...@apache.org> wrote: >> Author: hwright >> Date: Mon Feb 6 17:48:36 2012 >> New Revision: 1241097 >> >> URL: http://svn.apache.org/viewvc?rev=1241097&view=rev >> Log: >> Ev2 shims: Truthfully report our base checksum as being that of the empty >> stream. >> >> Note: This breaks several assumptions in various delta-editor receivers about >> the validity of this checksum. These have been patched to ignore the >> checksum >> if it is that of the empty stream. This will not affect correctness, as the >> final checksum, as supplied by close_file() is still used to detect >> corruption, >> and it hasn't changed. > > How does this even work? Sure, the checksum isn't checked, but the > delta-editor receiver is going to choose the wrong base contents to > apply the delta against.
Huh? The delta-editor receiver isn't using this to choose any base contents, it's simply using it as some kind of intermediate verification step. Before this change, we just passed a NULL checksum, which was *always* ignored, and everything Just Worked. With this change, we started being honest, and various pieces of the system didn't appreciate that honesty. -Hyrum -- uberSVN: Apache Subversion Made Easy http://www.uberSVN.com/
