From f85c8843c90046ba3029f0f395ba1aa6778792b6 Mon Sep 17 00:00:00 2001
From: Nicolas Martinelli <nim@odoo.com>
Date: Fri, 3 Nov 2017 12:57:34 +0100
Subject: [PATCH 1/2] [FIX] account, point_of_sale: tax with fixed amount

- Create a tax:
  Fixed amount: 10
  Price included
- Add it by default to a product costing 100
- In a SO/PO/Invoice, add 2 units of the product

The total price is 210 instead of 200.

opw-779696
---
 addons/account/models/account.py             |  2 +-
 addons/account/tests/test_tax.py             | 16 ++++++++++++++++
 addons/point_of_sale/static/src/js/models.js |  2 +-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/addons/account/models/account.py b/addons/account/models/account.py
index 2f9b3ee8bce..846cc9ea132 100644
--- a/addons/account/models/account.py
+++ b/addons/account/models/account.py
@@ -795,7 +795,7 @@ class AccountTax(models.Model):
                 incl_fixed_amount = incl_percent_amount = 0
             if tax.price_include:
                 if tax.amount_type == 'fixed':
-                    incl_fixed_amount += tax.amount
+                    incl_fixed_amount += quantity * tax.amount
                 elif tax.amount_type == 'percent':
                     incl_percent_amount += tax.amount
         # Start the computation of accumulated amounts at the total_excluded value.
diff --git a/addons/account/tests/test_tax.py b/addons/account/tests/test_tax.py
index f688e5ba9be..a214b8f35f8 100644
--- a/addons/account/tests/test_tax.py
+++ b/addons/account/tests/test_tax.py
@@ -232,6 +232,22 @@ class TestTax(AccountTestUsers):
             res
         )
 
+        self.fixed_tax.price_include = True
+        self.fixed_tax.include_base_amount = False
+        res = self.fixed_tax.compute_all(100.0, quantity=2.0)
+        self._check_compute_all_results(
+            180,     # 'base'
+            200,     # 'total_included'
+            180,     # 'total_excluded'
+            [
+                # base , amount     | seq | amount | incl | incl_base
+                # ---------------------------------------------------
+                (180.0, 20.0),    # |  1  |    20  |      |     t
+                # ---------------------------------------------------
+            ],
+            res
+        )
+
     def test_tax_include_base_amount_2(self):
         self.percent_tax.price_include = True
         self.percent_tax.amount = 21.0
diff --git a/addons/point_of_sale/static/src/js/models.js b/addons/point_of_sale/static/src/js/models.js
index 1df0dd7e3a0..08a21541e52 100644
--- a/addons/point_of_sale/static/src/js/models.js
+++ b/addons/point_of_sale/static/src/js/models.js
@@ -1434,7 +1434,7 @@ exports.Orderline = Backbone.Model.extend({
             }
             if(tax.price_include){
                 if(tax.amount_type === 'fixed')
-                    incl_fixed_amount += tax.amount;
+                    incl_fixed_amount += quantity * tax.amount;
                 else if(tax.amount_type === 'percent')
                     incl_percent_amount += tax.amount;
             }

From 6c996723b212b8ea85aa7b5d6e935d80e37b83a9 Mon Sep 17 00:00:00 2001
From: Nicolas Martinelli <nim@odoo.com>
Date: Fri, 3 Nov 2017 13:16:15 +0100
Subject: [PATCH 2/2] [FIX] point_of_sale: wrong variable name

`tax_amount` is not defined here, making it impossible to remove an
order line...
---
 addons/point_of_sale/static/src/js/models.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/addons/point_of_sale/static/src/js/models.js b/addons/point_of_sale/static/src/js/models.js
index 08a21541e52..ab6d7517d3e 100644
--- a/addons/point_of_sale/static/src/js/models.js
+++ b/addons/point_of_sale/static/src/js/models.js
@@ -1450,7 +1450,7 @@ exports.Orderline = Backbone.Model.extend({
             var amount = self._compute_all(tax, base, quantity, false);
 
             if(!tax.price_include || base_gaps.length == 0)
-                return tax_amount;
+                return amount;
 
             var new_gap = base_gaps[base_gaps.length - 1] - amount;