[abscondment]

> Also, shouldn't these simple bugs be quickly and fully discovered by automated tests?

Do you actually believe this?

Tests are a nice first pass, but they'll never fully discover every bug -- especially with a huge change like this.

[jamongkad]

Exactly as painful as it might seem. Automated tests can only get you so far. Sometimes you just have to suck it up and dig into the code base.