It appears that empty sysprefs will cause C4::Context->yaml_preference to crash. This patch should fix that so that yaml preference values don't cause any issues.
Created attachment 145239 [details] [review] Bug 32615: Don't crash on empty yaml sysprefs To test: 1) Apply patch 2) Verify tests in t/Context.t pass
I now realized it's only when adding a new syspref, setting the initial value to NULL that this is an issue. So very much of an edge case. I still don't see the harm of fixing this, but it's a very minor issue indeed.
Closing this one, I made a mistake testing this and appears undef/null values actually don't cause any issues.