Merge lp:~mallorymarcot/unifield-server/us-3837 into lp:unifield-server

[jftempo]

=== modified file 'bin/addons/purchase/purchase_order_line.py'
--- bin/addons/purchase/purchase_order_line.py	2017-11-26 18:37:44 +0000
+++ bin/addons/purchase/purchase_order_line.py	2017-12-13 16:51:34 +0000
@@ -1188,9 +1188,8 @@
         for line in self.browse(cr, uid, ids, context=context):
             new_vals = vals.copy()
             # check qty
-            if vals.get('product_qty', line.product_qty) <= 0.0 and \
-                    not line.order_id.rfq_ok and \
-                    'noraise' not in context and line.state != 'cancel':
+            if vals.get('product_qty', line.product_qty) <= 0.0 and not line.order_id.rfq_ok and 'noraise' not in context and \
+                line.state != 'cancel' and context.get('button', '') != 'cancel_only_pol' and vals.get('state', '') != 'cancel':
                 raise osv.except_osv(
                     _('Error'),
                     _('You can not have an order line with a negative or zero quantity')