diff --git a/addons/account/i18n/account.pot b/addons/account/i18n/account.pot
index 24525364a01..d978ea9b8b6 100644
--- a/addons/account/i18n/account.pot
+++ b/addons/account/i18n/account.pot
@@ -665,6 +665,16 @@ msgstr ""
 msgid "A tax fiscal position could be defined only one time on same taxes."
 msgstr ""
 
+#. module: account
+#: code:addons/account/models/res_users.py:17
+#, python-format
+msgid "A user cannot have both Tax B2B and Tax B2C.\n"
+"Problematic user(s): %s\n"
+"You should go in General Settings, and choose to display Product Prices\n"
+"either in 'Tax-Included' or in 'Tax-Excluded' mode\n"
+"(or switch twice the mode if you are already in the desired one)."
+msgstr ""
+
 #. module: account
 #: model:res.groups,name:account.group_warning_account
 msgid "A warning can be set on a partner (Account)"
diff --git a/addons/account/models/res_users.py b/addons/account/models/res_users.py
index 3e6fd163482..ab85e359d22 100644
--- a/addons/account/models/res_users.py
+++ b/addons/account/models/res_users.py
@@ -12,7 +12,15 @@ class Users(models.Model):
     @api.constrains('groups_id')
     def _check_one_user_type(self):
         super(Users, self)._check_one_user_type()
-        for user in self:
-            if (user.user_has_groups('account.group_show_line_subtotals_tax_included') and
-                    user.user_has_groups('account.group_show_line_subtotals_tax_excluded')):
-                raise ValidationError(_('A user cannot have both Tax B2B and Tax B2C'))
+
+        users_with_both_groups = self.filtered(lambda user:
+            user.user_has_groups('account.group_show_line_subtotals_tax_included') and
+            user.user_has_groups('account.group_show_line_subtotals_tax_excluded')
+        )
+        if users_with_both_groups:
+            names = ", ".join(users_with_both_groups.mapped('name'))
+            raise ValidationError(_("A user cannot have both Tax B2B and Tax B2C.\n"
+                                    "Problematic user(s): %s\n"
+                                    "You should go in General Settings, and choose to display Product Prices\n"
+                                    "either in 'Tax-Included' or in 'Tax-Excluded' mode\n"
+                                    "(or switch twice the mode if you are already in the desired one).") % names)
diff --git a/addons/mrp/models/mrp_production.py b/addons/mrp/models/mrp_production.py
index 170e2ddf0e8..a17867ab07f 100644
--- a/addons/mrp/models/mrp_production.py
+++ b/addons/mrp/models/mrp_production.py
@@ -671,7 +671,7 @@ class MrpProduction(models.Model):
             })
             if workorders:
                 workorders[-1].next_work_order_id = workorder.id
-                workorders[-1]._init_nextworkorder_states()
+                workorders[-1]._start_nextworkorder()
             workorders += workorder
 
             # assign moves; last operation receive all unassigned moves (which case ?)
diff --git a/addons/mrp/models/mrp_workorder.py b/addons/mrp/models/mrp_workorder.py
index d5b5aaae349..d688b10d1e3 100644
--- a/addons/mrp/models/mrp_workorder.py
+++ b/addons/mrp/models/mrp_workorder.py
@@ -343,9 +343,6 @@ class MrpWorkorder(models.Model):
                 move_line.lot_produced_id = self.final_lot_id.id
                 move_line.done_wo = True
 
-        # One a piece is produced, you can launch the next work order
-        self._start_nextworkorder()
-
         self.move_line_ids.filtered(
             lambda move_line: not move_line.done_move and not move_line.lot_produced_id and move_line.qty_done > 0
         ).write({
@@ -396,6 +393,9 @@ class MrpWorkorder(models.Model):
             self.final_lot_id.use_next_on_work_order_id = self.next_work_order_id
             self.final_lot_id = False
 
+        # One a piece is produced, you can launch the next work order
+        self._start_nextworkorder()
+
         # Set a qty producing
         rounding = self.production_id.product_uom_id.rounding
         if float_compare(self.qty_produced, self.production_id.product_qty, precision_rounding=rounding) >= 0:
@@ -417,12 +417,13 @@ class MrpWorkorder(models.Model):
 
     @api.multi
     def _start_nextworkorder(self):
-        for record in self:
-            if record.next_work_order_id.state == 'pending':
-                record.next_work_order_id.state = 'ready'
-
-    def _init_nextworkorder_states(self):
-        return 'pending'
+        rounding = self.product_id.uom_id.rounding
+        if self.next_work_order_id.state == 'pending' and (
+                (self.operation_id.batch == 'no' and
+                 float_compare(self.qty_production, self.qty_produced, precision_rounding=rounding) <= 0) or
+                (self.operation_id.batch == 'yes' and
+                 float_compare(self.operation_id.batch_size, self.qty_produced, precision_rounding=rounding) <= 0)):
+            self.next_work_order_id.state = 'ready'
 
     @api.multi
     def button_start(self):
diff --git a/addons/stock_account/models/stock.py b/addons/stock_account/models/stock.py
index a708f57e256..398b7d6d672 100644
--- a/addons/stock_account/models/stock.py
+++ b/addons/stock_account/models/stock.py
@@ -560,7 +560,7 @@ class StockMove(models.Model):
         debit_value = self.company_id.currency_id.round(valuation_amount)
 
         # check that all data is correct
-        if self.company_id.currency_id.is_zero(debit_value):
+        if self.company_id.currency_id.is_zero(debit_value) and not self.env['ir.config_parameter'].sudo().get_param('stock_account.allow_zero_cost'):
             raise UserError(_("The cost of %s is currently equal to 0. Change the cost or the configuration of your product to avoid an incorrect valuation.") % (self.product_id.display_name,))
         credit_value = debit_value
 
diff --git a/doc/cla/individual/hviniciusg.md b/doc/cla/individual/hviniciusg.md
new file mode 100644
index 00000000000..d98b0703a49
--- /dev/null
+++ b/doc/cla/individual/hviniciusg.md
@@ -0,0 +1,11 @@
+Bolivia, 2019-03-31
+
+I hereby agree to the terms of the Odoo Individual Contributor License
+Agreement v1.0.
+
+I declare that I am authorized and able to make this agreement and sign this
+declaration.
+
+Signed,
+
+Hugo Vinicius Garcia Razeara hviniciusg@gmail.com https://github.com/hviniciusg
diff --git a/odoo/tests/common.py b/odoo/tests/common.py
index fc70adb88a2..bc5a460bcd3 100644
--- a/odoo/tests/common.py
+++ b/odoo/tests/common.py
@@ -1461,12 +1461,13 @@ class Form(object):
                 return []
 
             v = []
-            c = {t[1]: t[2] for t in current if t[0] in (1, 2)} if current else {}
+            c = {t[1] for t in current if t[0] in (1, 2)} if current else set()
             # which view should this be???
             subfields = descr['views']['edition']['fields']
+            # TODO: simplistic, unlikely to work if e.g. there's a 5 inbetween other commands
             for command in value:
                 if command[0] in (0, 1):
-                    c.pop(command[1], None) # remove record from currents
+                    c.discard(command[1])
                     v.append((command[0], command[1], {
                         k: self._cleanup_onchange(
                             subfields[k], v, None
@@ -1475,9 +1476,11 @@ class Form(object):
                         if k in subfields
                     }))
                 elif command[0] == 2:
+                    c.discard(command[1])
                     v.append((2, command[1], False))
                 elif command[0] == 4:
-                    v.append((1, command[1], c.pop(command[1], {})))
+                    c.discard(command[1])
+                    v.append((1, command[1], {}))
                 elif command[0] == 5:
                     v = []
             # explicitly mark all non-relinked (or modified) records as deleted