Retain empty bib records (cat.bib.keep_on_empty) not honored with volume transfers

[Jason Etheridge]

The default behavior is for EG to auto-delete bibs that lose their last item, however this happens (item deletion, item transfer, or volume transfer). The library setting "Retain empty bib records" is supposed to prevent this behavior. In master (and 2.50 and 2.4.1), this doesn't work when you move the last items off of a bib through a volume transfer to a different a bib record. The originating bib record is deleted.

Here are the scenarios I tested:

Scenario 1:
 cat.bib.alert_on_empty = unset
 cat.bib.keep_on_empty = unset
 cat.volume.delete_on_empty = unset

 a) Delete last item results in:
  deleted bib, volume, item
 b) Delete last volume and item together results in:
  deleted bib, volume, item
 c) Transfer volume to lib on different bib:
  deleted bib
 d) Transfer item to a volume on a different bib:
  deleted bib, volume

Scenario 2:
 cat.bib.alert_on_empty = unset
 cat.bib.keep_on_empty = true (at Branch)
 cat.volume.delete_on_empty = unset

 a) Delete last item results in:
  deleted volume, item
 b) Delete last volume and item together results in:
  deleted volume, item
 c) Transfer volume to lib on different bib:
  deleted bib
 d) Transfer item to a volume on a different bib:
  deleted volume

I don't have a fix handy.

[Jason Stephenson (jstephenson)]

We've had this bug come up lately, so I made a branch to fix it:

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/dyrcona/lp1333893-volume-transfer-keep-empty-bib

[Beth Willis (willis-a)]

NOTE: I tested this code on our Evergreen 3.2.4 system only.

I have tested this code and consent to signing off on it with my name, Beth Willis and my email address, <email address hidden>

[Jason Stephenson (jstephenson)]

Pushed to master and rel_3_1 through rel_3_3 for the safety of empty bibs everywhere.

Thanks for testing, Beth!