There is nothing complicated in the CVS repository (at least not in this case). Branch (repository) A contains commits C3a, C4, C6a, C8, and C9, in that order, and B contains commits C2, C3b, C5, C6b, C7, and C10. C3a and C3b have exactly the same delta, but are separate commits (of course, in CVS every file is committed separately anyway). Same thing with C6a and C6b. The way these commits were made is typically that the change was made in a working copy of one of the branches and tested there, then ported over to a working copy of the other branch (either by hand, or by using cvs diff + patch) and tested there too. Then both changes were committed using the same cvs commit command, which would commit each file in sequence, but due to the low precision of the timestamps they would appear to have happend simultanously.
Making a checkout of a branch by date ambiguous is definitiely not something we'd want, so I guess that means that variant is out for sure.
