users: Use browser locale to set the default language of new user.

This commit reads the browser locale during user registration, and
sets it as default language of user if it is supported by Zulip.
Otherwise, it is set to realm's default language.

zerver/actions/create_user.py

@@ -344,6 +344,7 @@ def do_create_user(
     tos_version: Optional[str] = None,
     timezone: str = "",
     avatar_source: str = UserProfile.AVATAR_FROM_GRAVATAR,
+    default_language: str = "en",
     default_sending_stream: Optional[Stream] = None,
     default_events_register_stream: Optional[Stream] = None,
     default_all_public_streams: Optional[bool] = None,
@@ -367,6 +368,7 @@ def do_create_user(
             tos_version=tos_version,
             timezone=timezone,
             avatar_source=avatar_source,
+            default_language=default_language,
             default_sending_stream=default_sending_stream,
             default_events_register_stream=default_events_register_stream,
             default_all_public_streams=default_all_public_streams,

zerver/lib/create_user.py

@@ -84,6 +84,7 @@ def create_user_profile(
     is_mirror_dummy: bool,
     tos_version: Optional[str],
     timezone: Optional[str],
+    default_language: str = "en",
     tutorial_status: str = UserProfile.TUTORIAL_WAITING,
     enter_sends: bool = False,
     force_id: Optional[int] = None,
@@ -116,7 +117,7 @@ def create_user_profile(
         tutorial_status=tutorial_status,
         enter_sends=enter_sends,
         onboarding_steps=orjson.dumps([]).decode(),
-        default_language=realm.default_language,
+        default_language=default_language,
         delivery_email=email,
         **extra_kwargs,
     )
@@ -143,6 +144,7 @@ def create_user(
     timezone: str = "",
     avatar_source: str = UserProfile.AVATAR_FROM_GRAVATAR,
     is_mirror_dummy: bool = False,
+    default_language: str = "en",
     default_sending_stream: Optional[Stream] = None,
     default_events_register_stream: Optional[Stream] = None,
     default_all_public_streams: Optional[bool] = None,
@@ -162,6 +164,7 @@ def create_user(
         is_mirror_dummy,
         tos_version,
         timezone,
+        default_language,
         force_id=force_id,
         force_date_joined=force_date_joined,
     )

zerver/tests/test_signup.py

@@ -3933,8 +3933,7 @@ class UserSignUpTest(InviteUserBase):
 
     def test_user_default_language_and_timezone(self) -> None:
         """
-        Check if the default language of new user is the default language
+        Check if the default language of new user is set using the browser locale
-        of the realm.
         """
         email = self.nonreg_email("newguy")
         password = "newpassword"
@@ -3954,12 +3953,42 @@ class UserSignUpTest(InviteUserBase):
         self.assertEqual(result.status_code, 200)
 
         # Pick a password and agree to the ToS.
-        result = self.submit_reg_form_for_user(email, password, timezone=timezone)
+        result = self.submit_reg_form_for_user(
+            email, password, timezone=timezone, HTTP_ACCEPT_LANGUAGE="fr,en;q=0.9"
+        )
+        self.assertEqual(result.status_code, 302)
+
+        user_profile = self.nonreg_user("newguy")
+        self.assertNotEqual(user_profile.default_language, realm.default_language)
+        self.assertEqual(user_profile.default_language, "fr")
+        self.assertEqual(user_profile.timezone, timezone)
+        from django.core.mail import outbox
+
+        outbox.pop()
+
+    def test_default_language_with_unsupported_browser_locale(self) -> None:
+        email = self.nonreg_email("newguy")
+        password = "newpassword"
+        realm = get_realm("zulip")
+        do_set_realm_property(realm, "default_language", "de", acting_user=None)
+
+        result = self.client_post("/accounts/home/", {"email": email})
+        self.assertEqual(result.status_code, 302)
+        self.assertTrue(result["Location"].endswith(f"/accounts/send_confirm/{email}"))
+        result = self.client_get(result["Location"])
+        self.assert_in_response("Check your email so we can get started.", result)
+
+        # Visit the confirmation link.
+        confirmation_url = self.get_confirmation_url_from_outbox(email)
+        result = self.client_get(confirmation_url)
+        self.assertEqual(result.status_code, 200)
+
+        # Pick a password and agree to the ToS.
+        result = self.submit_reg_form_for_user(email, password, HTTP_ACCEPT_LANGUAGE="en-IND")
         self.assertEqual(result.status_code, 302)
 
         user_profile = self.nonreg_user("newguy")
         self.assertEqual(user_profile.default_language, realm.default_language)
-        self.assertEqual(user_profile.timezone, timezone)
         from django.core.mail import outbox
 
         outbox.pop()

zerver/views/registration.py

@@ -44,6 +44,7 @@ from zerver.forms import (
 )
 from zerver.lib.email_validation import email_allowed_for_realm, validate_email_not_already_in_realm
 from zerver.lib.exceptions import RateLimited
+from zerver.lib.i18n import get_default_language_for_new_user
 from zerver.lib.pysa import mark_sanitized
 from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.send_email import EmailNotDeliveredException, FromAddress, send_email
@@ -432,6 +433,12 @@ def accounts_register(
             do_change_password(user_profile, password)
             do_change_full_name(user_profile, full_name, user_profile)
             do_change_user_setting(user_profile, "timezone", timezone, acting_user=user_profile)
+            do_change_user_setting(
+                user_profile,
+                "default_language",
+                get_default_language_for_new_user(request, realm),
+                acting_user=None,
+            )
             # TODO: When we clean up the `do_activate_mirror_dummy_user` code path,
             # make it respect invited_as_admin / is_realm_admin.
 
@@ -445,6 +452,7 @@ def accounts_register(
                 role=role,
                 tos_version=settings.TERMS_OF_SERVICE_VERSION,
                 timezone=timezone,
+                default_language=get_default_language_for_new_user(request, realm),
                 default_stream_groups=default_stream_groups,
                 source_profile=source_profile,
                 realm_creation=realm_creation,