Source deletion can race with build publication and leave binaries forever

[William Grant]

PublishingSet.requestDeletion on an SPPH can race with build publication and leave some of the source's BPPHs published forever. The misbehaviour occurs when an SPPH is deleted while at least one of its builds' PackageUploads is still in ACCEPTED, having been through process-upload but not yet process-accepted. The BPPHs don't yet exist, so won't be deleted, but once the publisher runs they will exist with Published and remain so until further manual intervention.

(The main negative consequence is repeated no-op republications of suites with affected sources (bug #685033). Pre-acceptance rejection was added as the fix for bug #684180, but this part of the race survived. Bug #528459 has similar consequences but occurs when a Superseded source leaves NBS binaries.)

[William Grant (wgrant)]

http://pastebin.ubuntu.com/23269289/ conservatively calculates affected BPPHs.