While working on MBS-7190, I noticed that the code for merging release events contains another serious bug. If the source releases both have a release event for a common country, all release events from the merge target will be discarded. If in addition there is a reason to take at least one other release event from the target (because it has a more complete date), all release events from both sides will be discarded.

First case:

• release A: UK 2013, Germany 2013
• release B: France 2013, Germany 2013
• result of merging into B: UK 2013, Germany 2013

Second case:

• release A: UK 2013, Germany 2013, Italy 2013
• release B: France 2013, Germany 2013, Italy 2013-04
• result of merging into B: no release events

I'd expect the first case at least to be not that uncommon, yet I couldn't find a ticket, so either my expectation is wrong or nobody noticed the bug before. It is present since the (re)introduction of multiple release events.

Fix to be submitted this evening.