SmartSite@UCDavis - 2.6.4.2 - Sakai 2.6.2 - Server "ucddev1"
gb v1.4.0-a5

TEST PROCESS -
site XXX 123 123w011 where I tested w/new items and it failed
1 – designated negative number for drop lowest in existing category – fail (which means I can't do it)
get error box saying drop lowest must be positive integer BUT initially the negative number appears to hold when I edit the category again, multiple times. refresh gets it back to 0 but I think it was misleading initially. after multiple tries it works each time...that is drop lowest reverts to 0.
2 – created new category and designated negative number for drop lowest - fail
get error box as above.
3 – trying neg category weight AND neg drop lowest gets both error messages in box - ok
4 – changing either to positive gets the appropriate error for the remaining negative number – ok
5 - tried to change item weight in category to negative number - fail
6 - created new item to test negative number in item weight, but in the new item edit box there is not option to specify item weight. I assume this is how it's supposed to be?? so you can't create an item with ANY weight, much less a negative one - ok

QA RESULTS -
pass for existing and new categories

I rescind my pass.
see comments from today in grbk-786.
this works the same way. ie:
you can't EDIT an existing category to drop a negative number.
in creating a NEW category, a negative drop lowest number is accepted.

SmartSite@UCDavis - 2.6.4.2 - Sakai 2.6.2 - Server "ucddev1"
gb2 v1.4.0-a4
firefox and ie8

TEST PLAN -
sites CCC 123 123 w11 (weighted categories)
1 – for category w/ =weighted items, entered negative values in drop lowest box
2 – box accepts negative number (w/o red outline as in grbk-786) but attempt to save gets request failed w/explanation box popup, drop lowest box reverts to 0
DDD 123 123 w11 (categories)
1 – created category w/items of = point values
2 – same results as #2 above

RESULTS -
pass

r72185

There appears to be some server side validation, but somehow in hosted mode it is not used.