Comment 3 for bug 1564378

I may have been a little light on details I suppose. The change should be harmless though; I tested the current style against the implied undef style in my patch with a little throwaway perl program and it worked the same either way, though if %hash = (); is more idiomatic for hashes that's fine with me too. A quick grep -r shows that both types are used: 33 () to 143 undef.

I'm seeing it during fine generation during calls to open-ils.storage.action.circulation.overdue.generate_fines. These conditions have to be true to hit the warning (which they were here about 2000 times this morning. D: ):
It has to be the first Overdue fine applied to a transaction to call extend_grace_period
Grace period must be 24 hours or longer
The circ_lib must enable the circ.grace.extend OU and have hours of operation specified for at least one day
If all of the above are true the code will finally reach the line that triggers the warning.