[FIX] web: show decimal part of floats in exported xlsx

If the decimal separator of the currently selected language is a comma,
exporting data in an xlsx would use a wrong float format

Steps to reproduce:
1. Install Invoicing
2. Go to Settings > Languages, add 'French / Français' language and
   switch to it
3. Go to Facturation > Fournisseurs > Factures
4. Export the data (there should be at least one amount with a decimal
   part)
5. The decimal part of the amounts is not displayed

Solution:
Always use the same decimal separator to print in the xlsx as we can
only use a dot as a decimal separator (the comma is used as the thousand
separator). The value will then be displayed to the user according to
his OS regional settings (see https://xlsxwriter.readthedocs.io/format.html#number-formats-in-different-locales)

Problem:
When using a comma for the float format, we actually specify the format
of the integral part of the number (the thousands) without displaying
the decimal part (which is represented with the dot)

opw-2965984

closes odoo/odoo#102255

X-original-commit: 21efa4f18266a5c5c57157035c2357ed3e147a69
Signed-off-by: Julien Castiaux <juc@odoo.com>
Signed-off-by: Guillaume Merlin (megu) <megu@odoo.com>

addons/test_xlsx_export/tests/test_export.py

@@ -6,6 +6,7 @@ from unittest.mock import patch
 
 from odoo import http
 from odoo.tests import common, tagged
+from odoo.tools.misc import get_lang
 from odoo.addons.web.controllers.export import ExportXlsxWriter
 from odoo.addons.mail.tests.common import mail_new_test_user
 
@@ -373,3 +374,20 @@ class TestGroupedExport(XlsxCreatorCase):
             ['    1000.0 (1)', '1000.000'],
             ['3', '1000.00'],
         ])
+
+    def test_decimal_separator(self):
+        """ The decimal separator of the language used shouldn't impact the float representation in the exported xlsx """
+        get_lang(self.env).decimal_point = ','
+        get_lang(self.env).thousands_sep = '.'
+
+        values = [
+                {'int_sum': 1, 'float_min': 86420.864},
+        ]
+        export = self.export(values, fields=['int_sum', 'float_min'], params={'groupby': ['int_sum', 'float_min']})
+
+        self.assertExportEqual(export, [
+            ['Int Sum'          ,'Float Min'],
+            ['1 (1)'            ,'86420.86'],
+            ['    86420.864 (1)','86420.86'],
+            ['1'                ,'86420.86'],
+        ])

addons/web/controllers/export.py

@@ -17,7 +17,7 @@ from odoo import http
 from odoo.exceptions import UserError
 from odoo.http import content_disposition, request
 from odoo.tools import lazy_property, osutil, pycompat
-from odoo.tools.misc import xlsxwriter, get_lang
+from odoo.tools.misc import xlsxwriter
 from odoo.tools.translate import _
 
 
@@ -183,11 +183,10 @@ class ExportXlsxWriter:
         self.datetime_style = self.workbook.add_format({'text_wrap': True, 'num_format': 'yyyy-mm-dd hh:mm:ss'})
         self.worksheet = self.workbook.add_worksheet()
         self.value = False
-        decimal_separator = get_lang(request.env).decimal_point
-        self.float_format = f'0{decimal_separator}00'
+        self.float_format = '#,##0.00'
         decimal_places = [res['decimal_places'] for res in
                           request.env['res.currency'].search_read([], ['decimal_places'])]
-        self.monetary_format = f'0{decimal_separator}{max(decimal_places or [2]) * "0"}'
+        self.monetary_format = f'#,##0.{max(decimal_places or [2]) * "0"}'
 
         if row_count > self.worksheet.xls_rowmax:
             raise UserError(_('There are too many rows (%s rows, limit: %s) to export as Excel 2007-2013 (.xlsx) format. Consider splitting the export.') % (row_count, self.worksheet.xls_rowmax))