I was wondering, how do you treat automerges that go through without conflicts? Do you just verify via compile / unit tests and then commit, or do you take a look at each merge result to ensure that there are no other, semantic issues, that might cause an error only once the app is running?
This is a matter of convention, and up to the team working on the project.
Ideally you should have unit tests covering all execution paths, and appropriate non-regression tests. There should be a continuous integration system that runs all automated tests after every commit, including auto-merge commits, and a dedicated QA team to run additional non-automated tests.
In reality you probably have something in between the ideal setup and nothing at all, and it's up to the team where they draw the line, and how much carefulness is "enough". In a super-critical project you obviously want to be as careful as possible, but in your pet project not so much.