On Thu, Jul 12, 2012 at 3:43 PM, Julian Foad <julianf...@btopenworld.com>wrote:
> Stefan Fuhrmann wrote: > > In Berlin, Julian raised the question how relevant the criss-cross > > merge case actually. I think I found a reasonable merge policy > > where those cases become the norm rather than an exception. > > > > Most people seem to do what one might call "unqualified" catch-up > > merges, i.e. "merge everything up to HEAD" regardless of HEAD's > > state with respect to stability, features, side-effects etc. > > > > From a process perspective, it seems much more prudent to > > do "qualified" merges like "merge from /trunk up to the last > > fully tested nightly build revision" and "merge from branch up > > to the point that I think is safe". > > Yes, that makes sense. > > > In both directions, there will > > be changes between the catch-up source from A to B and > > the merge commit form B to A (and vice versa). > > I don't quite follow that last sentence. > Taking your diagram, I was trying to say that there are revisions between the qualified / starred revisions and the revisions where the merges got committed. > Even if it was > > the same person doing the merge in both directions, this > > situation could not be avoided. > > > So, in a bit more detail, the situation is like this: > > A = /trunk Tested versions * * > > A o---o---o---o---o---o---o---o---o---o---o---o---o > \ \____ / > > \ ____\ __/ > > \ / \ > > B o---o---o---o---o---o---o---o---o---o---o > Safe versions * * > > 1 2 3 > > Sequence of events: > 1. Nightly testing. > > 2. Catch up branch from latest stable trunk. > 3. Reintegrate branch to trunk, from latest tested version of branch. > > That sort of scenario? > Exactly. The thing is that at this point the graph does not even depend on whether the changes to a given node actually produce a conflict. If the history processing code had any problems with this kind of merge graph, that problem would surface more often than actual conflicts. -- Stefan^2. -- Certified & Supported Apache Subversion Downloads: http://www.wandisco.com/subversion/download
