Merge pull request #14977 from cpennington/cale/fix-learner-542

Cale/fix learner 542

cms/envs/aws.py

@@ -221,6 +221,8 @@ GIT_REPO_EXPORT_DIR = ENV_TOKENS.get('GIT_REPO_EXPORT_DIR', '/edx/var/edxapp/exp
 # Translation overrides
 LANGUAGES = ENV_TOKENS.get('LANGUAGES', LANGUAGES)
 LANGUAGE_CODE = ENV_TOKENS.get('LANGUAGE_CODE', LANGUAGE_CODE)
+LANGUAGE_COOKIE = ENV_TOKENS.get('LANGUAGE_COOKIE', LANGUAGE_COOKIE)
+
 USE_I18N = ENV_TOKENS.get('USE_I18N', USE_I18N)
 
 ENV_FEATURES = ENV_TOKENS.get('FEATURES', {})

cms/envs/common.py

@@ -547,6 +547,8 @@ TIME_ZONE = 'America/New_York'  # http://en.wikipedia.org/wiki/List_of_tz_zones_
 LANGUAGE_CODE = 'en'  # http://www.i18nguy.com/unicode/language-identifiers.html
 LANGUAGES_BIDI = lms.envs.common.LANGUAGES_BIDI
 
+LANGUAGE_COOKIE = lms.envs.common.LANGUAGE_COOKIE
+
 LANGUAGES = lms.envs.common.LANGUAGES
 LANGUAGE_DICT = dict(LANGUAGES)
 

common/djangoapps/student/cookies.py

@@ -17,7 +17,7 @@ from student.models import CourseEnrollment
 CREATE_LOGON_COOKIE = Signal(providing_args=['user', 'response'])
 
 
-def _get_cookie_settings(request):
+def standard_cookie_settings(request):
     """ Returns the common cookie settings (e.g. expiration time). """
 
     if request.session.get_expire_at_browser_close():
@@ -73,7 +73,7 @@ def set_logged_in_cookies(request, response, user):
         HttpResponse
 
     """
-    cookie_settings = _get_cookie_settings(request)
+    cookie_settings = standard_cookie_settings(request)
 
     # Backwards compatibility: set the cookie indicating that the user
     # is logged in.  This is just a boolean value, so it's not very useful.
@@ -96,7 +96,7 @@ def set_logged_in_cookies(request, response, user):
 
 def set_user_info_cookie(response, request):
     """ Sets the user info cookie on the response. """
-    cookie_settings = _get_cookie_settings(request)
+    cookie_settings = standard_cookie_settings(request)
 
     # In production, TLS should be enabled so that this cookie is encrypted
     # when we send it.  We also need to set "secure" to True so that the browser

lms/djangoapps/ccx/tests/test_field_override_performance.py

@@ -231,18 +231,18 @@ class TestFieldOverrideMongoPerformance(FieldOverridePerformanceTestCase):
         #     # of sql queries to default,
         #     # of mongo queries,
         # )
-        ('no_overrides', 1, True, False): (25, 1),
-        ('no_overrides', 2, True, False): (25, 1),
-        ('no_overrides', 3, True, False): (25, 1),
-        ('ccx', 1, True, False): (25, 1),
-        ('ccx', 2, True, False): (25, 1),
-        ('ccx', 3, True, False): (25, 1),
-        ('no_overrides', 1, False, False): (25, 1),
-        ('no_overrides', 2, False, False): (25, 1),
-        ('no_overrides', 3, False, False): (25, 1),
-        ('ccx', 1, False, False): (25, 1),
-        ('ccx', 2, False, False): (25, 1),
-        ('ccx', 3, False, False): (25, 1),
+        ('no_overrides', 1, True, False): (23, 1),
+        ('no_overrides', 2, True, False): (23, 1),
+        ('no_overrides', 3, True, False): (23, 1),
+        ('ccx', 1, True, False): (23, 1),
+        ('ccx', 2, True, False): (23, 1),
+        ('ccx', 3, True, False): (23, 1),
+        ('no_overrides', 1, False, False): (23, 1),
+        ('no_overrides', 2, False, False): (23, 1),
+        ('no_overrides', 3, False, False): (23, 1),
+        ('ccx', 1, False, False): (23, 1),
+        ('ccx', 2, False, False): (23, 1),
+        ('ccx', 3, False, False): (23, 1),
     }
 
 
@@ -254,19 +254,19 @@ class TestFieldOverrideSplitPerformance(FieldOverridePerformanceTestCase):
     __test__ = True
 
     TEST_DATA = {
-        ('no_overrides', 1, True, False): (25, 3),
-        ('no_overrides', 2, True, False): (25, 3),
-        ('no_overrides', 3, True, False): (25, 3),
-        ('ccx', 1, True, False): (25, 3),
-        ('ccx', 2, True, False): (25, 3),
-        ('ccx', 3, True, False): (25, 3),
-        ('ccx', 1, True, True): (26, 3),
-        ('ccx', 2, True, True): (26, 3),
-        ('ccx', 3, True, True): (26, 3),
-        ('no_overrides', 1, False, False): (25, 3),
-        ('no_overrides', 2, False, False): (25, 3),
-        ('no_overrides', 3, False, False): (25, 3),
-        ('ccx', 1, False, False): (25, 3),
-        ('ccx', 2, False, False): (25, 3),
-        ('ccx', 3, False, False): (25, 3),
+        ('no_overrides', 1, True, False): (23, 3),
+        ('no_overrides', 2, True, False): (23, 3),
+        ('no_overrides', 3, True, False): (23, 3),
+        ('ccx', 1, True, False): (23, 3),
+        ('ccx', 2, True, False): (23, 3),
+        ('ccx', 3, True, False): (23, 3),
+        ('ccx', 1, True, True): (24, 3),
+        ('ccx', 2, True, True): (24, 3),
+        ('ccx', 3, True, True): (24, 3),
+        ('no_overrides', 1, False, False): (23, 3),
+        ('no_overrides', 2, False, False): (23, 3),
+        ('no_overrides', 3, False, False): (23, 3),
+        ('ccx', 1, False, False): (23, 3),
+        ('ccx', 2, False, False): (23, 3),
+        ('ccx', 3, False, False): (23, 3),
     }

lms/djangoapps/courseware/tests/test_course_info.py

@@ -367,7 +367,7 @@ class SelfPacedCourseInfoTestCase(LoginEnrollmentTestCase, SharedModuleStoreTest
         self.assertEqual(resp.status_code, 200)
 
     def test_num_queries_instructor_paced(self):
-        self.fetch_course_info_with_queries(self.instructor_paced_course, 21, 4)
+        self.fetch_course_info_with_queries(self.instructor_paced_course, 18, 4)
 
     def test_num_queries_self_paced(self):
-        self.fetch_course_info_with_queries(self.self_paced_course, 21, 4)
+        self.fetch_course_info_with_queries(self.self_paced_course, 18, 4)

lms/djangoapps/courseware/tests/test_i18n.py

@@ -2,6 +2,7 @@
 Tests i18n in courseware
 """
 
+import json
 import re
 
 from django.conf import settings
@@ -14,8 +15,6 @@ from nose.plugins.attrib import attr
 
 from openedx.core.djangoapps.dark_lang.models import DarkLangConfig
 from openedx.core.djangoapps.lang_pref import LANGUAGE_KEY
-from openedx.core.djangoapps.user_api.preferences.api import set_user_preference
-from student.models import UserProfile
 from student.tests.factories import UserFactory
 
 
@@ -61,8 +60,7 @@ class BaseI18nTestCase(TestCase):
         """
         # Create one user and save it to the database
         email = 'test@edx.org'
-        self.user = UserFactory.build(username='test', email=email, password=self.pwd)
-        self.user.save()
+        self.user = UserFactory.create(username='test', email=email, password=self.pwd)
 
     def user_login(self):
         """
@@ -119,7 +117,6 @@ class I18nRegressionTests(BaseI18nTestCase):
 
     def test_unreleased_lang_resolution(self):
         # Regression test; LOC-85
-        UserProfile.objects.create(user=self.user)
         self.release_languages('fa')
         self.user_login()
 
@@ -136,7 +133,6 @@ class I18nRegressionTests(BaseI18nTestCase):
         self.assert_tag_has_attr(response.content, "html", "lang", "fa-ir")
 
     def test_preview_lang(self):
-        UserProfile.objects.create(user=self.user)
         self.user_login()
 
         # Regression test; LOC-87
@@ -172,9 +168,17 @@ class I18nLangPrefTests(BaseI18nTestCase):
     """
     def setUp(self):
         super(I18nLangPrefTests, self).setUp()
-        UserProfile.objects.create(user=self.user)
         self.user_login()
 
+    def set_lang_preference(self, language):
+        """Sets the user's language preference, allowing the LangPref middleware to operate to set the preference cookie."""
+        response = self.client.patch(
+            reverse('preferences_api', args=[self.user.username]),
+            json.dumps({LANGUAGE_KEY: language}),
+            content_type="application/merge-patch+json"
+        )
+        self.assertEqual(response.status_code, 204)
+
     def test_lang_preference(self):
         # Regression test; LOC-87
         self.release_languages('ar, es-419')
@@ -184,13 +188,13 @@ class I18nLangPrefTests(BaseI18nTestCase):
         self.assert_tag_has_attr(response.content, "html", "lang", self.site_lang)
 
         # Set user language preference
-        set_user_preference(self.user, LANGUAGE_KEY, 'ar')
+        self.set_lang_preference('ar')
         # and verify we now get an ar response
         response = self.client.get(self.url)
         self.assert_tag_has_attr(response.content, "html", "lang", 'ar')
 
         # Verify that switching language preference gives the right language
-        set_user_preference(self.user, LANGUAGE_KEY, 'es-419')
+        self.set_lang_preference('es-419')
         response = self.client.get(self.url)
         self.assert_tag_has_attr(response.content, "html", "lang", 'es-419')
 
@@ -199,7 +203,7 @@ class I18nLangPrefTests(BaseI18nTestCase):
         self.release_languages('ar, es-419')
 
         # Set user language preference
-        set_user_preference(self.user, LANGUAGE_KEY, 'ar')
+        self.set_lang_preference('ar')
         # Verify preview-lang takes precedence
         self.client.post(self.preview_language_url, {'preview_lang': 'eo', 'set_language': 'set_language'})
         response = self.client.get(self.url)

lms/djangoapps/courseware/tests/test_views.py

@@ -206,8 +206,8 @@ class IndexQueryTestCase(ModuleStoreTestCase):
     NUM_PROBLEMS = 20
 
     @ddt.data(
-        (ModuleStoreEnum.Type.mongo, 10, 147),
-        (ModuleStoreEnum.Type.split, 4, 147),
+        (ModuleStoreEnum.Type.mongo, 10, 141),
+        (ModuleStoreEnum.Type.split, 4, 141),
     )
     @ddt.unpack
     def test_index_query_counts(self, store_type, expected_mongo_query_count, expected_mysql_query_count):
@@ -1408,12 +1408,12 @@ class ProgressPageTests(ModuleStoreTestCase):
         """Test that query counts remain the same for self-paced and instructor-paced courses."""
         SelfPacedConfiguration(enabled=self_paced_enabled).save()
         self.setup_course(self_paced=self_paced)
-        with self.assertNumQueries(42), check_mongo_calls(1):
+        with self.assertNumQueries(39), check_mongo_calls(1):
             self._get_progress_page()
 
     @ddt.data(
-        (False, 42, 28),
-        (True, 35, 24)
+        (False, 39, 25),
+        (True, 32, 21)
     )
     @ddt.unpack
     def test_progress_queries(self, enable_waffle, initial, subsequent):

lms/djangoapps/django_comment_client/base/tests.py

@@ -377,8 +377,8 @@ class ViewsQueryCountTestCase(
         return inner
 
     @ddt.data(
-        (ModuleStoreEnum.Type.mongo, 3, 4, 31),
-        (ModuleStoreEnum.Type.split, 3, 13, 31),
+        (ModuleStoreEnum.Type.mongo, 3, 4, 30),
+        (ModuleStoreEnum.Type.split, 3, 13, 30),
     )
     @ddt.unpack
     @count_queries
@@ -386,8 +386,8 @@ class ViewsQueryCountTestCase(
         self.create_thread_helper(mock_request)
 
     @ddt.data(
-        (ModuleStoreEnum.Type.mongo, 3, 3, 27),
-        (ModuleStoreEnum.Type.split, 3, 10, 27),
+        (ModuleStoreEnum.Type.mongo, 3, 3, 26),
+        (ModuleStoreEnum.Type.split, 3, 10, 26),
     )
     @ddt.unpack
     @count_queries

lms/envs/aws.py

@@ -315,6 +315,8 @@ TIME_ZONE = ENV_TOKENS.get('TIME_ZONE', TIME_ZONE)
 LANGUAGES = ENV_TOKENS.get('LANGUAGES', LANGUAGES)
 LANGUAGE_DICT = dict(LANGUAGES)
 LANGUAGE_CODE = ENV_TOKENS.get('LANGUAGE_CODE', LANGUAGE_CODE)
+LANGUAGE_COOKIE = ENV_TOKENS.get('LANGUAGE_COOKIE', LANGUAGE_COOKIE)
+
 USE_I18N = ENV_TOKENS.get('USE_I18N', USE_I18N)
 
 # Additional installed apps

lms/envs/common.py

@@ -863,6 +863,8 @@ LANGUAGE_CODE = 'en'  # http://www.i18nguy.com/unicode/language-identifiers.html
 # these languages display right to left
 LANGUAGES_BIDI = ("he", "ar", "fa", "ur", "fa-ir", "rtl")
 
+LANGUAGE_COOKIE = "openedx-language-preference"
+
 # Sourced from http://www.localeplanet.com/icu/ and wikipedia
 LANGUAGES = (
     ('en', u'English'),

lms/envs/devstack_docker.py

@@ -30,6 +30,7 @@ FEATURES.update({
     'ENABLE_COURSEWARE_SEARCH': False,
     'ENABLE_COURSE_DISCOVERY': False,
     'ENABLE_DASHBOARD_SEARCH': False,
+    'SHOW_LANGUAGE_SELECTOR': True
 })
 
 ENABLE_MKTG_SITE = os.environ.get('ENABLE_MARKETING_SITE', False)

openedx/core/djangoapps/bookmarks/tests/test_views.py

@@ -268,7 +268,7 @@ class BookmarksListViewTests(BookmarksViewsTestsBase):
         self.assertEqual(response.data['developer_message'], u'Parameter usage_id not provided.')
 
         # Send empty data dictionary.
-        with self.assertNumQueries(8):  # No queries for bookmark table.
+        with self.assertNumQueries(7):  # No queries for bookmark table.
             response = self.send_post(
                 client=self.client,
                 url=reverse('bookmarks'),

openedx/core/djangoapps/lang_pref/__init__.py

@@ -4,3 +4,7 @@ Useful information for setting the language preference
 
 # this is the UserPreference key for the user's preferred language
 LANGUAGE_KEY = 'pref-lang'
+
+LANGUAGE_HEADER = 'HTTP_ACCEPT_LANGUAGE'
+
+COOKIE_DURATION = 14 * 24 * 60 * 60  # 14 days in seconds

openedx/core/djangoapps/lang_pref/middleware.py

@@ -2,12 +2,17 @@
 Middleware for Language Preferences
 """
 
+from django.conf import settings
 from django.utils.translation import LANGUAGE_SESSION_KEY
 from django.utils.translation.trans_real import parse_accept_lang_header
 
-from openedx.core.djangoapps.lang_pref import LANGUAGE_KEY
-from openedx.core.djangoapps.lang_pref.api import released_languages
-from openedx.core.djangoapps.user_api.preferences.api import get_user_preference, delete_user_preference
+from openedx.core.djangoapps.lang_pref import (
+    LANGUAGE_KEY, LANGUAGE_HEADER, COOKIE_DURATION
+)
+from openedx.core.djangoapps.user_api.preferences.api import (
+    get_user_preference, delete_user_preference, set_user_preference
+)
+from openedx.core.djangoapps.user_api.errors import UserAPIInternalError, UserAPIRequestError
 
 
 class LanguagePreferenceMiddleware(object):
@@ -21,17 +26,46 @@ class LanguagePreferenceMiddleware(object):
     def process_request(self, request):
         """
         If a user's UserPreference contains a language preference, use the user's preference.
+        Save the current language preference cookie as the user's preferred language.
         """
-        languages = released_languages()
-        system_released_languages = [seq[0] for seq in languages]
+        cookie_lang = request.COOKIES.get(settings.LANGUAGE_COOKIE, None)
+        if cookie_lang:
+            if request.user.is_authenticated():
+                set_user_preference(request.user, LANGUAGE_KEY, cookie_lang)
 
+            accept_header = request.META.get(LANGUAGE_HEADER, None)
+            if accept_header:
+                current_langs = parse_accept_lang_header(accept_header)
+                # Promote the cookie_lang over any language currently in the accept header
+                current_langs = [(lang, qvalue) for (lang, qvalue) in current_langs if lang != cookie_lang]
+                current_langs.insert(0, (cookie_lang, 1))
+                accept_header = ",".join("{};q={}".format(lang, qvalue) for (lang, qvalue) in current_langs)
+            else:
+                accept_header = cookie_lang
+            request.META[LANGUAGE_HEADER] = accept_header
+
+    def process_response(self, request, response):
         # If the user is logged in, check for their language preference
-        if request.user.is_authenticated():
+        if getattr(request, 'user', None) and request.user.is_authenticated():
             # Get the user's language preference
-            user_pref = get_user_preference(request.user, LANGUAGE_KEY)
-            # Set it to the LANGUAGE_SESSION_KEY (Django-specific session setting governing language pref)
-            if user_pref:
-                if user_pref in system_released_languages:
-                    request.session[LANGUAGE_SESSION_KEY] = user_pref
+            try:
+                user_pref = get_user_preference(request.user, LANGUAGE_KEY)
+            except (UserAPIRequestError, UserAPIInternalError):
+                # If we can't find the user preferences, then don't modify the cookie
+                pass
+            else:
+                # Set it in the LANGUAGE_COOKIE
+                if user_pref:
+                    response.set_cookie(
+                        settings.LANGUAGE_COOKIE,
+                        value=user_pref,
+                        domain=settings.SESSION_COOKIE_DOMAIN,
+                        max_age=COOKIE_DURATION,
+                    )
                 else:
-                    delete_user_preference(request.user, LANGUAGE_KEY)
+                    response.delete_cookie(
+                        settings.LANGUAGE_COOKIE,
+                        domain=settings.SESSION_COOKIE_DOMAIN
+                    )
+
+        return response

openedx/core/djangoapps/lang_pref/views.py

@@ -9,7 +9,7 @@ from django.http import HttpResponse
 from django.views.decorators.csrf import ensure_csrf_cookie
 from django.utils.translation import LANGUAGE_SESSION_KEY
 
-from openedx.core.djangoapps.lang_pref import LANGUAGE_KEY
+from openedx.core.djangoapps.lang_pref import LANGUAGE_KEY, COOKIE_DURATION
 
 
 @ensure_csrf_cookie
@@ -17,9 +17,16 @@ def update_session_language(request):
     """
     Update the language session key.
     """
+    response = HttpResponse(200)
     if request.method == 'PATCH':
         data = json.loads(request.body)
         language = data.get(LANGUAGE_KEY, settings.LANGUAGE_CODE)
         if request.session.get(LANGUAGE_SESSION_KEY, None) != language:
             request.session[LANGUAGE_SESSION_KEY] = unicode(language)
-    return HttpResponse(200)
+        response.set_cookie(
+            settings.LANGUAGE_COOKIE,
+            language,
+            domain=settings.SESSION_COOKIE_DOMAIN,
+            max_age=COOKIE_DURATION
+        )
+    return response

openedx/core/djangoapps/user_api/accounts/tests/test_views.py

@@ -174,7 +174,7 @@ class TestOwnUsernameAPI(CacheIsolationTestCase, UserAPITestCase):
         Test that a client (logged in) can get her own username.
         """
         self.client.login(username=self.user.username, password=TEST_PASSWORD)
-        self._verify_get_own_username(15)
+        self._verify_get_own_username(14)
 
     def test_get_username_inactive(self):
         """
@@ -184,7 +184,7 @@ class TestOwnUsernameAPI(CacheIsolationTestCase, UserAPITestCase):
         self.client.login(username=self.user.username, password=TEST_PASSWORD)
         self.user.is_active = False
         self.user.save()
-        self._verify_get_own_username(15)
+        self._verify_get_own_username(14)
 
     def test_get_username_not_logged_in(self):
         """
@@ -305,7 +305,7 @@ class TestAccountsAPI(CacheIsolationTestCase, UserAPITestCase):
         """
         self.different_client.login(username=self.different_user.username, password=TEST_PASSWORD)
         self.create_mock_profile(self.user)
-        with self.assertNumQueries(19):
+        with self.assertNumQueries(18):
             response = self.send_get(self.different_client)
         self._verify_full_shareable_account_response(response, account_privacy=ALL_USERS_VISIBILITY)
 
@@ -320,7 +320,7 @@ class TestAccountsAPI(CacheIsolationTestCase, UserAPITestCase):
         """
         self.different_client.login(username=self.different_user.username, password=TEST_PASSWORD)
         self.create_mock_profile(self.user)
-        with self.assertNumQueries(19):
+        with self.assertNumQueries(18):
             response = self.send_get(self.different_client)
         self._verify_private_account_response(response, account_privacy=PRIVATE_VISIBILITY)
 
@@ -395,12 +395,12 @@ class TestAccountsAPI(CacheIsolationTestCase, UserAPITestCase):
             self.assertEqual(False, data["accomplishments_shared"])
 
         self.client.login(username=self.user.username, password=TEST_PASSWORD)
-        verify_get_own_information(17)
+        verify_get_own_information(16)
 
         # Now make sure that the user can get the same information, even if not active
         self.user.is_active = False
         self.user.save()
-        verify_get_own_information(11)
+        verify_get_own_information(10)
 
     def test_get_account_empty_string(self):
         """
@@ -414,7 +414,7 @@ class TestAccountsAPI(CacheIsolationTestCase, UserAPITestCase):
         legacy_profile.save()
 
         self.client.login(username=self.user.username, password=TEST_PASSWORD)
-        with self.assertNumQueries(17):
+        with self.assertNumQueries(16):
             response = self.send_get(self.client)
         for empty_field in ("level_of_education", "gender", "country", "bio"):
             self.assertIsNone(response.data[empty_field])

openedx/core/djangoapps/user_api/errors.py

@@ -83,6 +83,7 @@ class PreferenceValidationError(PreferenceRequestError):
     """
     def __init__(self, preference_errors):
         self.preference_errors = preference_errors
+        super(PreferenceValidationError, self).__init__(preference_errors)
 
 
 class PreferenceUpdateError(PreferenceRequestError):
@@ -93,6 +94,7 @@ class PreferenceUpdateError(PreferenceRequestError):
     def __init__(self, developer_message, user_message=None):
         self.developer_message = developer_message
         self.user_message = user_message
+        super(PreferenceUpdateError, self).__init__(developer_message)
 
 
 class CountryCodeError(ValueError):

openedx/core/djangoapps/user_api/helpers.py

@@ -6,6 +6,7 @@ from collections import defaultdict
 from functools import wraps
 import logging
 import json
+import traceback
 
 from django import forms
 from django.core.serializers.json import DjangoJSONEncoder
@@ -65,16 +66,19 @@ def intercept_errors(api_error, ignore_errors=None):
                         LOGGER.warning(msg)
                         raise
 
+                caller = traceback.format_stack(limit=2)[0]
+
                 # Otherwise, log the error and raise the API-specific error
                 msg = (
                     u"An unexpected error occurred when calling '{func_name}' "
-                    u"with arguments '{args}' and keyword arguments '{kwargs}': "
+                    u"with arguments '{args}' and keyword arguments '{kwargs}' from {caller}: "
                     u"{exception}"
                 ).format(
                     func_name=func.func_name,
                     args=args,
                     kwargs=kwargs,
-                    exception=ex.developer_message if hasattr(ex, 'developer_message') else repr(ex)
+                    exception=ex.developer_message if hasattr(ex, 'developer_message') else repr(ex),
+                    caller=caller.strip(),
                 )
                 LOGGER.exception(msg)
                 raise api_error(msg)
@@ -502,3 +506,13 @@ def shim_student_view(view_func, check_logged_in=False):
         return response
 
     return _inner
+
+
+def serializer_is_dirty(preference_serializer):
+    """
+    Return True if saving the supplied (Raw)UserPreferenceSerializer would change the database.
+    """
+    return (
+        preference_serializer.instance is None or
+        preference_serializer.instance.value != preference_serializer.validated_data['value']
+    )

openedx/core/djangoapps/user_api/preferences/api.py

@@ -20,7 +20,7 @@ from ..errors import (
     UserAPIInternalError, UserAPIRequestError, UserNotFound, UserNotAuthorized,
     PreferenceValidationError, PreferenceUpdateError, CountryCodeError
 )
-from ..helpers import intercept_errors
+from ..helpers import intercept_errors, serializer_is_dirty
 from ..models import UserOrgTag, UserPreference
 from ..serializers import UserSerializer, RawUserPreferenceSerializer
 
@@ -142,7 +142,9 @@ def update_user_preferences(requesting_user, update, user=None):
         if preference_value is not None:
             try:
                 serializer = serializers[preference_key]
-                serializer.save()
+
+                if serializer_is_dirty(serializer):
+                    serializer.save()
             except Exception as error:
                 raise _create_preference_update_error(preference_key, preference_value, error)
         else:
@@ -177,10 +179,12 @@ def set_user_preference(requesting_user, preference_key, preference_value, usern
     existing_user = _get_authorized_user(requesting_user, username)
     serializer = create_user_preference_serializer(existing_user, preference_key, preference_value)
     validate_user_preference_serializer(serializer, preference_key, preference_value)
-    try:
-        serializer.save()
-    except Exception as error:
-        raise _create_preference_update_error(preference_key, preference_value, error)
+
+    if serializer_is_dirty(serializer):
+        try:
+            serializer.save()
+        except Exception as error:
+            raise _create_preference_update_error(preference_key, preference_value, error)
 
 
 @intercept_errors(UserAPIInternalError, ignore_errors=[UserAPIRequestError])
@@ -310,7 +314,13 @@ def _get_authorized_user(requesting_user, username=None, allow_staff=False):
     If username is not provided, requesting_user.username is assumed.
     """
     if username is None:
-        username = requesting_user.username
+        # If the user is one that has already been stored to the database, use that
+        if requesting_user.pk:
+            return requesting_user
+        else:
+            # Otherwise, treat this as a request against a separate user
+            username = requesting_user.username
+
     try:
         existing_user = User.objects.get(username=username)
     except ObjectDoesNotExist:
@@ -347,13 +357,13 @@ def create_user_preference_serializer(user, preference_key, preference_value):
     except ObjectDoesNotExist:
         existing_user_preference = None
     new_data = {
-        "user": user.id,
         "key": preference_key,
         "value": preference_value,
     }
     if existing_user_preference:
-        serializer = RawUserPreferenceSerializer(existing_user_preference, data=new_data)
+        serializer = RawUserPreferenceSerializer(existing_user_preference, data=new_data, partial=True)
     else:
+        new_data['user'] = user.id
         serializer = RawUserPreferenceSerializer(data=new_data)
     return serializer
 

openedx/core/djangoapps/user_api/preferences/tests/test_api.py

@@ -53,9 +53,8 @@ class TestPreferenceAPI(CacheIsolationTestCase):
         super(TestPreferenceAPI, self).setUp()
         self.user = UserFactory.create(password=self.password)
         self.different_user = UserFactory.create(password=self.password)
-        self.staff_user = UserFactory(is_staff=True, password=self.password)
-        self.no_such_user = UserFactory.create(password=self.password)
-        self.no_such_user.username = "no_such_user"
+        self.staff_user = UserFactory.create(is_staff=True, password=self.password)
+        self.no_such_user = UserFactory.build(password=self.password, username="no_such_user")
         self.test_preference_key = "test_key"
         self.test_preference_value = "test_value"
         set_user_preference(self.user, self.test_preference_key, self.test_preference_value)

openedx/core/djangoapps/user_api/serializers.py

@@ -22,12 +22,7 @@ class UserSerializer(serializers.HyperlinkedModelSerializer):
         """
         Return the name attribute from the user profile object if profile exists else none
         """
-        try:
-            profile = UserProfile.objects.get(user=user)
-        except UserProfile.DoesNotExist:
-            return None
-
-        return profile.name
+        return user.profile.name
 
     def get_preferences(self, user):
         """

openedx/core/djangoapps/user_api/tests/test_helpers.py

@@ -2,6 +2,7 @@
 Tests for helper functions.
 """
 import json
+import re
 import mock
 import ddt
 from django import forms
@@ -55,19 +56,31 @@ class InterceptErrorsTest(TestCase):
         exception = 'openedx.core.djangoapps.user_api.tests.test_helpers.FakeInputException'
         expected_log_msg = (
             u"An unexpected error occurred when calling 'intercepted_function' with arguments '()' and "
-            u"keyword arguments '{'raise_error': <class '" + exception + u"'>}': FakeInputException()"
-        )
+            u"keyword arguments '{{'raise_error': <class '{}'>}}' "
+            u"from File \"{}\", line XXX, in test_logs_errors\n"
+            u"    intercepted_function(raise_error=FakeInputException): FakeInputException()"
+        ).format(exception, __file__)
 
         # Verify that the raised exception has the error message
         try:
             intercepted_function(raise_error=FakeInputException)
         except FakeOutputException as ex:
-            self.assertEqual(ex.message, expected_log_msg)
+            actual_message = re.sub(r'line \d+', 'line XXX', ex.message, flags=re.MULTILINE)
+            self.assertEqual(actual_message, expected_log_msg)
 
         # Verify that the error logger is called
         # This will include the stack trace for the original exception
         # because it's called with log level "ERROR"
-        mock_logger.exception.assert_called_once_with(expected_log_msg)
+        calls = mock_logger.exception.mock_calls
+        self.assertEqual(len(calls), 1)
+        name, args, kwargs = calls[0]
+
+        self.assertEqual(name, '')
+        self.assertEqual(len(args), 1)
+        self.assertEqual(kwargs, {})
+
+        actual_message = re.sub(r'line \d+', 'line XXX', args[0], flags=re.MULTILINE)
+        self.assertEqual(actual_message, expected_log_msg)
 
 
 class FormDescriptionTest(TestCase):

openedx/core/djangoapps/user_api/views.py

@@ -1002,7 +1002,7 @@ class UserViewSet(viewsets.ReadOnlyModelViewSet):
     """
     authentication_classes = (authentication.SessionAuthentication,)
     permission_classes = (ApiKeyHeaderPermission,)
-    queryset = User.objects.all().prefetch_related("preferences")
+    queryset = User.objects.all().prefetch_related("preferences").select_related("profile")
     serializer_class = UserSerializer
     paginate_by = 10
     paginate_by_param = "page_size"
@@ -1028,7 +1028,7 @@ class ForumRoleUsersListView(generics.ListAPIView):
             raise ParseError('course_id must be specified')
         course_id = SlashSeparatedCourseKey.from_deprecated_string(course_id_string)
         role = Role.objects.get_or_create(course_id=course_id, name=name)[0]
-        users = role.users.all()
+        users = role.users.prefetch_related("preferences").select_related("profile").all()
         return users
 
 
@@ -1057,7 +1057,7 @@ class PreferenceUsersListView(generics.ListAPIView):
     paginate_by_param = "page_size"
 
     def get_queryset(self):
-        return User.objects.filter(preferences__key=self.kwargs["pref_key"]).prefetch_related("preferences")
+        return User.objects.filter(preferences__key=self.kwargs["pref_key"]).prefetch_related("preferences").select_related("profile")
 
 
 class UpdateEmailOptInPreference(APIView):