[FIX] *: remove en_US as fallback for lang code

en_US may not be activated as it is possible to create a database in
another language using the database manager.

When trying to install a chart of account, the tax return entry tried
to format a date at the installation of the module, with no lang in
the context. The fallback was made on en_US but an error is raised if
that language is not activated.

As it is a very common scenario to retrieve a language from the
context, add a generic tool method to do it.

Replace and closes odoo/odoo#37629

closes odoo/odoo#37568

Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

5 files changed, 31 insertions, 18 deletions

diff --git a/odoo/addons/base/models/ir_qweb.py b/odoo/addons/base/models/ir_qweb.py
index 0ddb06744e0..07fe2d1592f 100644
--- a/odoo/addons/base/models/ir_qweb.py
+++ b/odoo/addons/base/models/ir_qweb.py
@@ -13,6 +13,7 @@ from werkzeug import urls
 
 from odoo import api, models, tools
 from odoo.tools.safe_eval import assert_valid_codeobj, _BUILTINS, _SAFE_OPCODES
+from odoo.tools.misc import get_lang
 from odoo.http import request
 from odoo.modules.module import get_resource_path
 
@@ -112,7 +113,7 @@ class IrQWeb(models.AbstractModel, QWeb):
         return super(IrQWeb, self).compile(id_or_xml_id, options=options)
 
     def load(self, name, options):
-        lang = options.get('lang', 'en_US')
+        lang = options.get('lang', get_lang(self.env).code)
         env = self.env
         if lang != env.context.get('lang'):
             env = env(context=dict(env.context, lang=lang))
@@ -148,7 +149,7 @@ class IrQWeb(models.AbstractModel, QWeb):
     # compile directives
 
     def _compile_directive_lang(self, el, options):
-        lang = el.attrib.pop('t-lang', 'en_US')
+        lang = el.attrib.pop('t-lang', get_lang(self.env).code)
         if el.get('t-call-options'):
             el.set('t-call-options', el.get('t-call-options')[0:-1] + u', "lang": %s}' % lang)
         else:
diff --git a/odoo/addons/base/models/ir_qweb_fields.py b/odoo/addons/base/models/ir_qweb_fields.py
index c275707377b..329d9b3c55b 100644
--- a/odoo/addons/base/models/ir_qweb_fields.py
+++ b/odoo/addons/base/models/ir_qweb_fields.py
@@ -10,6 +10,7 @@ from lxml import etree
 import math
 
 from odoo.tools import html_escape as escape, posix_to_ldml, safe_eval, float_utils, format_date, format_duration, pycompat
+from odoo.tools.misc import get_lang
 
 import logging
 _logger = logging.getLogger(__name__)
@@ -130,13 +131,11 @@ class FieldConverter(models.AbstractModel):
         """ user_lang()
 
         Fetches the res.lang record corresponding to the language code stored
-        in the user's context. Fallbacks to en_US if no lang is present in the
-        context *or the language code is not valid*.
+        in the user's context.
 
         :returns: Model[res.lang]
         """
-        lang_code = self._context.get('lang') or 'en_US'
-        return self.env['res.lang']._lang_get(lang_code)
+        return get_lang(self.env)
 
 
 class IntegerConverter(models.AbstractModel):
diff --git a/odoo/models.py b/odoo/models.py
index 0a076effedd..479b86bbf01 100644
--- a/odoo/models.py
+++ b/odoo/models.py
@@ -56,7 +56,7 @@ from .tools import frozendict, lazy_classproperty, lazy_property, ormcache, \
                    groupby
 from .tools.config import config
 from .tools.func import frame_codeinfo
-from .tools.misc import CountingStream, clean_context, DEFAULT_SERVER_DATETIME_FORMAT, DEFAULT_SERVER_DATE_FORMAT
+from .tools.misc import CountingStream, clean_context, DEFAULT_SERVER_DATETIME_FORMAT, DEFAULT_SERVER_DATE_FORMAT, get_lang
 from .tools.safe_eval import safe_eval
 from .tools.translate import _
 from .tools import date_utils
@@ -1991,7 +1991,7 @@ class BaseModel(MetaModel('DummyModel', (object,), {'_register': False})):
                 if ftype == 'many2one':
                     value = value[0]
                 elif ftype in ('date', 'datetime'):
-                    locale = self._context.get('lang') or 'en_US'
+                    locale = get_lang(self.env).code
                     fmt = DEFAULT_SERVER_DATETIME_FORMAT if ftype == 'datetime' else DEFAULT_SERVER_DATE_FORMAT
                     tzinfo = None
                     range_start = value
diff --git a/odoo/osv/expression.py b/odoo/osv/expression.py
index e15ea963abd..38d503af0f9 100644
--- a/odoo/osv/expression.py
+++ b/odoo/osv/expression.py
@@ -123,6 +123,7 @@ from zlib import crc32
 from datetime import date, datetime, time
 import odoo.modules
 from odoo.tools import pycompat
+from odoo.tools.misc import get_lang
 from ..models import MAGIC_COLUMNS, BaseModel
 import odoo.tools as tools
 
@@ -1145,7 +1146,7 @@ class expression(object):
 
                     params = (
                         model._name + ',' + left,
-                        model.env.lang or 'en_US',
+                        get_lang(model.env).code,
                         'model',
                         right,
                     )
diff --git a/odoo/tools/misc.py b/odoo/tools/misc.py
index a9268db1eed..b65cd23cf6f 100644
--- a/odoo/tools/misc.py
+++ b/odoo/tools/misc.py
@@ -1162,6 +1162,21 @@ else:
     def html_escape(text):
         return werkzeug.utils.escape(text)
 
+
+def get_lang(env, lang_code=False):
+    """
+    Retrieve the first lang object installed, by checking the parameter lang_code,
+    the context and then the company. If no lang is installed from those variables,
+    fallback on the first lang installed in the system.
+    :param str lang_code: the locale (i.e. en_US)
+    :return res.lang: the first lang found that is installed on the system.
+    """
+    langs = [code for code, _ in env['res.lang'].get_installed()]
+    for code in [lang_code, env.context.get('lang'), env.user.company_id.partner_id.lang, langs[0]]:
+        if code in langs:
+            return env['res.lang']._lang_get(code)
+
+
 def formatLang(env, value, digits=None, grouping=True, monetary=False, dp=False, currency_obj=False):
     """
         Assuming 'Account' decimal.precision=3:
@@ -1182,9 +1197,7 @@ def formatLang(env, value, digits=None, grouping=True, monetary=False, dp=False,
     if isinstance(value, str) and not value:
         return ''
 
-    langs = [code for code, _ in env['res.lang'].get_installed()]
-    lang_code = env.context['lang'] if env.context.get('lang') in langs else (env.user.company_id.partner_id.lang or langs[0])
-    lang_obj = env['res.lang']._lang_get(lang_code)
+    lang_obj = get_lang(env)
 
     res = lang_obj.format('%.' + str(digits) + 'f', value, grouping=grouping, monetary=monetary)
 
@@ -1221,7 +1234,7 @@ def format_date(env, value, lang_code=False, date_format=False):
         else:
             value = odoo.fields.Datetime.from_string(value)
 
-    lang = env['res.lang']._lang_get(lang_code or env.context.get('lang') or 'en_US')
+    lang = get_lang(env, lang_code)
     locale = babel.Locale.parse(lang.code)
     if not date_format:
         date_format = posix_to_ldml(lang.date_format, locale=locale)
@@ -1240,7 +1253,7 @@ def parse_date(env, value, lang_code=False):
         :return: date object from the localized string
         :rtype: datetime.date
     '''
-    lang = env['res.lang']._lang_get(lang_code or env.context.get('lang') or 'en_US')
+    lang = get_lang(env, lang_code)
     locale = babel.Locale.parse(lang.code)
     try:
         return babel.dates.parse_date(value, locale=locale)
@@ -1271,8 +1284,7 @@ def format_datetime(env, value, tz=False, dt_format='medium', lang_code=False):
     except Exception:
         localized_datetime = utc_datetime
 
-    lang_code = lang_code or env.context.get('lang') or 'en_US'
-    lang = env['res.lang']._lang_get(lang_code)
+    lang = get_lang(env, lang_code)
 
     locale = babel.Locale.parse(lang.code or lang_code)  # lang can be inactive, so `lang`is empty
     if not dt_format:
@@ -1302,7 +1314,7 @@ def format_time(env, value, tz=False, time_format='medium', lang_code=False):
     if not value:
         return ''
 
-    lang = env['res.lang']._lang_get(lang_code or env.context.get('lang') or 'en_US')
+    lang = get_lang(env, lang_code)
     locale = babel.Locale.parse(lang.code)
     if not time_format:
         time_format = posix_to_ldml(lang.time_format, locale=locale)
@@ -1320,7 +1332,7 @@ def _format_time_ago(env, time_delta, lang_code=False, add_direction=True):
 
 def format_amount(env, amount, currency, lang_code=False):
     fmt = "%.{0}f".format(currency.decimal_places)
-    lang = env['res.lang']._lang_get(lang_code or env.context.get('lang') or 'en_US')
+    lang = get_lang(env, lang_code)
 
     formatted_amount = lang.format(fmt, currency.round(amount), grouping=True, monetary=True)\
         .replace(r' ', u'\N{NO-BREAK SPACE}').replace(r'-', u'-\N{ZERO WIDTH NO-BREAK SPACE}')