Re: [PATCH OSSTEST v1] ap-fetch-version: Arrange for osstest merges from upstream to be stable

[Ian Campbell <ian.campbell@citrix.com>]

On Wed, 2015-07-08 at 16:23 +0100, Ian Jackson wrote:
> Ian Campbell writes ("[PATCH OSSTEST v1] ap-fetch-version: Arrange for osstest merges from upstream to be stable"):
> > If a downstream osstest instance has nothing to test it its local
> > pretest then it will attempt to merge from the upstream instance. If
> > this fails then it will try again and again generating a new merge
> > commit each time, even if upstream has not moved.
> > 
> > It is desirable that these merges instead be stable i.e. the same if
> > the inputs have not changed. This is good for potential bisection
> > attempts, history reporting/mining as well as just being sensible.
> > 
> > Here we arrange for this by recording the last merge "epoch" (being
> > the first merge of the current input branches) in a new branch
> > "merge-epoch" in the local testing.git and comparing our fresh merge
> > against it.
> > 
> > If the tree and parents are the same then the merge is effectively
> > identical (it may/will differ in the date) and we reuse the epoch
> > merge.
> > 
> > If they new merge does not match then something has changed (i.e.
> > upstream has moved on) and so we take the new merge and establish a
> > new epoch.
> > 
> > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> 
> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

Thanks. I've put this into the Cambridge instance's pretest, and will
send a pull request to merge back the result when it has baked there.

Ian.