Comment 1 for bug 929723

Note that if multiple changes with dependencies get merged at once (because their ancestor is merged) there will be one merge commit used for all the changes. Example:

* e501593 Merge changes Ic9f0d336,Ia4a7402a,I8a62490c
|\
| * c83efb1 test c
| * d3ab4ca test b
| * 57c10a0 test a
* | 3c194f3 test merge
|/
* 9c2d83c common head

(test a, test b, and test c (all based on "common head" were merged into "test merge" via the gerrit generated merge commit on top))

In that case we may be using the same merge commit sha1 for multiple events. It's probably the correct thing to do, however, we'll want to know that when writing jenkins jobs. We may end up making the same tarball twice (however, it should be the _same_ tarball, for whatever that's worth).