diff --git a/issue12109.diff b/issue12109.diff
new file mode 100644
index 0000000..5a3cfca
--- /dev/null
+++ b/issue12109.diff
@@ -0,0 +1,137 @@
+diff --git a/tryton/modules/purchase/purchase.py b/tryton/modules/purchase/purchase.py
+index faf35cecfa..bb564ff9f4 100644
+--- a/tryton/modules/purchase/purchase.py
++++ b/tryton/modules/purchase/purchase.py
+@@ -1091,16 +1091,13 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
+             'company': Eval('company', None),
+             },
+         search_context={
+-            'locations': If(Bool(Eval('_parent_purchase', {}).get(
+-                        'warehouse')),
+-                [Eval('_parent_purchase', {}).get('warehouse', None)],
+-                []),
+-            'stock_date_end': Eval('_parent_purchase', {}).get(
+-                'purchase_date'),
++            'locations': If(Bool(Eval('warehouse')),
++                [Eval('warehouse', -1)], []),
++            'stock_date_end': Eval('purchase_date', None),
+             'stock_skip_warehouse': True,
+-            'currency': Eval('_parent_purchase', {}).get('currency'),
+-            'supplier': Eval('_parent_purchase', {}).get('party'),
+-            'purchase_date': Eval('_parent_purchase', {}).get('purchase_date'),
++            'currency': Eval('currency', -1),
++            'supplier': Eval('supplier', -1),
++            'purchase_date': Eval('purchase_date', None),
+             'uom': Eval('unit'),
+             'taxes': Eval('taxes', []),
+             'quantity': Eval('quantity'),
+@@ -1119,7 +1116,7 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
+                     ('product', '=', Eval('product')),
+                     ],
+                 []),
+-            ('party', '=', Eval('_parent_purchase', {}).get('party')),
++            ('party', '=', Eval('supplier', -1)),
+             ],
+         states={
+             'invisible': Eval('type') != 'line',
+@@ -1153,8 +1150,7 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
+         domain=[('parent', '=', None), ['OR',
+                 ('group', '=', None),
+                 ('group.kind', 'in', ['purchase', 'both'])],
+-                ('company', '=',
+-                    Eval('_parent_purchase', {}).get('company', -1)),
++                ('company', '=', Eval('company', -1)),
+             ],
+         states={
+             'invisible': Eval('type') != 'line',
+@@ -1170,6 +1166,9 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
+     move_done = fields.Function(fields.Boolean('Moves Done'), 'get_move_done')
+     move_exception = fields.Function(fields.Boolean('Moves Exception'),
+             'get_move_exception')
++    warehouse = fields.Function(fields.Many2One(
++            'stock.location', "Warehouse"),
++        'on_change_with_warehouse')
+     from_location = fields.Function(fields.Many2One('stock.location',
+             'From Location'), 'get_from_location')
+     to_location = fields.Function(fields.Many2One('stock.location',
+@@ -1437,6 +1436,11 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
+             return amount
+         return Decimal('0.0')
+
++    @fields.depends('purchase', '_parent_purchase.warehouse')
++    def on_change_with_warehouse(self, name=None):
++        if self.purchase and self.purchase.warehouse:
++            return self.purchase.warehouse.id
++
+     def get_from_location(self, name):
+         if (self.quantity or 0) >= 0:
+             if self.purchase.party.supplier_location:
+diff --git a/tryton/modules/sale/sale.py b/tryton/modules/sale/sale.py
+index 1b0e36a3b3..6c85325b2b 100644
+--- a/tryton/modules/sale/sale.py
++++ b/tryton/modules/sale/sale.py
+@@ -1143,13 +1143,13 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
+             'company': Eval('company', None),
+             },
+         search_context={
+-            'locations': If(Bool(Eval('_parent_sale', {}).get('warehouse')),
+-                [Eval('_parent_sale', {}).get('warehouse', 0)], []),
+-            'stock_date_end': Eval('_parent_sale', {}).get('sale_date'),
++            'locations': If(Bool(Eval('warehouse')),
++                [Eval('warehouse', -1)], []),
++            'stock_date_end': Eval('sale_date', None),
+             'stock_skip_warehouse': True,
+-            'currency': Eval('_parent_sale', {}).get('currency'),
+-            'customer': Eval('_parent_sale', {}).get('party'),
+-            'sale_date': Eval('_parent_sale', {}).get('sale_date'),
++            'currency': Eval('currency', -1),
++            'customer': Eval('customer', -1),
++            'sale_date': Eval('sale_date', None),
+             'uom': Eval('unit'),
+             'taxes': Eval('taxes', []),
+             'quantity': Eval('quantity'),
+@@ -1186,8 +1186,7 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
+         domain=[('parent', '=', None), ['OR',
+                 ('group', '=', None),
+                 ('group.kind', 'in', ['sale', 'both'])],
+-                ('company', '=',
+-                    Eval('_parent_sale', {}).get('company', -1)),
++                ('company', '=', Eval('company', -1)),
+             ],
+         states={
+             'invisible': Eval('type') != 'line',
+@@ -1205,7 +1204,7 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
+     move_exception = fields.Function(fields.Boolean('Moves Exception'),
+             'get_move_exception')
+     warehouse = fields.Function(fields.Many2One('stock.location',
+-            'Warehouse'), 'get_warehouse')
++            'Warehouse'), 'on_change_with_warehouse')
+     from_location = fields.Function(fields.Many2One('stock.location',
+             'From Location'), 'get_from_location')
+     to_location = fields.Function(fields.Many2One('stock.location',
+@@ -1427,8 +1426,10 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
+             return amount
+         return Decimal('0.0')
+
+-    def get_warehouse(self, name):
+-        return self.sale.warehouse.id if self.sale.warehouse else None
++    @fields.depends('sale', '_parent_sale.warehouse')
++    def on_change_with_warehouse(self, name=None):
++        if self.sale and self.sale.warehouse:
++            return self.sale.warehouse.id
+
+     def get_from_location(self, name):
+         if (self.quantity or 0) >= 0:
+diff --git a/tryton/modules/sale_product_customer/sale.py b/tryton/modules/sale_product_customer/sale.py
+index 4f0c4cca41..f77870d05f 100644
+--- a/tryton/modules/sale_product_customer/sale.py
++++ b/tryton/modules/sale_product_customer/sale.py
+@@ -22,7 +22,7 @@ class Line(metaclass=PoolMeta):
+                     ('product', '=', Eval('product')),
+                     ],
+                 []),
+-            ('party', '=', Eval('_parent_sale', {}).get('party')),
++            ('party', '=', Eval('customer', -1)),
+             ],
+         states={
+             'invisible': Eval('type') != 'line',