Comment 8 for bug 677074

Assuming you had two all but entirely filled in rulesets that differ in their duration rules and copy circ lib/user home lib setting. One has the copy circ lib, the other has the user home lib. Normally the two rows are equal in weight, but if they both match the user/item in the same way (lets say exactly) then the two rules are in an ambiguous state.

The code as I presented it would order the two rules by the database id to ensure consistent ordering every time. But, without knowing that, you have no way of determining which is which. And the database id may be lower on the one you care less about.

With a small weight adjustment you could push one to be slightly more important than the other, but perhaps not enough to change things when they don't match quite so exactly.

When fallthrough comes along I could see a major adjustment being used for something like a hard due date setting. Turn the dial to eleven for a specific permission group but only specify the hard due date option, not the duration or fine rule options. That rule will trump other rules for the hard due date, but regular ordering would resume afterward.