fix(translate): corrected string ordering

The project and category language views defaulted to wrong ordering and
didn't show a component switch reliably.

Fixes #19613

Author: nijel

docs/changes.rst

@@ -13,6 +13,7 @@ Weblate 2026.6
 .. rubric:: Bug fixes
 
 * Searching for strings with content changes without a recorded author now supports ``changed_by:""``.
+* Project-language translation sessions now keep strings grouped by component priority and show component switch warnings reliably.
 
 .. rubric:: Compatibility
 

weblate/trans/models/unit.py

@@ -78,6 +78,16 @@
 NEWLINES = re.compile(r"\r\n|\r|\n")
 
 
+def orders_units_by_component(obj: object) -> bool:
+    """Return whether the object scope spans component-ordered units."""
+    if isinstance(obj, (Project, Category)):
+        return True
+
+    from weblate.utils.stats import CategoryLanguage, ProjectLanguage  # noqa: PLC0415
+
+    return isinstance(obj, (ProjectLanguage, CategoryLanguage))
+
+
 def fill_in_source_translation(units: Iterable[Unit]) -> None:
     """
     Inject source translation into component from the source unit.
@@ -282,7 +292,7 @@ def order_by_request(self, form_data, obj) -> UnitQuerySet:
         if not sort_list:
             if hasattr(obj, "component") and obj.component.is_glossary:
                 sort_list = ["source"]
-            elif isinstance(obj, (Project, Category)):
+            elif orders_units_by_component(obj):
                 sort_list = [
                     # Show locked components at the end
                     "translation__component__locked",
@@ -292,6 +302,7 @@ def order_by_request(self, form_data, obj) -> UnitQuerySet:
                     "translation__component__is_glossary",
                     "translation__component__name",
                     "-priority",
+                    "position",
                 ]
             else:
                 sort_list = ["-priority", "position"]

weblate/trans/tests/test_edit.py

@@ -1354,6 +1354,52 @@ def test_revert_history_after_component_move_uses_current_translate_url(
             f'href="{translate_url}?checksum={unit.checksum}&revert={change.id}"',
         )
 
+    def test_project_language_warns_when_switching_component(self) -> None:
+        Component.objects.filter(pk=self.component.pk).update(priority=120)
+        high_component = self.create_po(name="High", priority=80, project=self.project)
+        high_translation = high_component.translation_set.get(
+            language=self.translation.language
+        )
+        translate_url = ProjectLanguage(
+            self.project, self.translation.language
+        ).get_translate_url()
+        high_component_offset = high_translation.unit_set.count()
+
+        response = self.client.get(translate_url, {"offset": high_component_offset})
+        self.assertNotContains(response, "You have shifted from")
+
+        response = self.client.get(translate_url, {"offset": high_component_offset + 1})
+        self.assertContains(response, "You have shifted from")
+
+    def test_project_language_ignores_stale_component_shift_unit(self) -> None:
+        Component.objects.filter(pk=self.component.pk).update(priority=120)
+        high_component = self.create_po(name="High", priority=80, project=self.project)
+        high_translation = high_component.translation_set.get(
+            language=self.translation.language
+        )
+        translate_url = ProjectLanguage(
+            self.project, self.translation.language
+        ).get_translate_url()
+        high_component_offset = high_translation.unit_set.count()
+
+        response = self.client.get(translate_url, {"offset": high_component_offset})
+        self.assertEqual(response.status_code, 200)
+
+        stale_unit_id = Unit.objects.order_by("-pk").values_list("pk", flat=True)[0] + 1
+        session = self.client.session
+        search_key = next(key for key in session if key.startswith("search_"))
+        session_result = session[search_key]
+        session_result["last_viewed_unit_id"] = stale_unit_id
+        session[search_key] = session_result
+        session.save()
+
+        response = self.client.get(translate_url, {"offset": high_component_offset + 1})
+        self.assertEqual(response.status_code, 200)
+        self.assertNotContains(response, "You have shifted from")
+        self.assertNotEqual(
+            self.client.session[search_key]["last_viewed_unit_id"], stale_unit_id
+        )
+
     def test_revert_plural(self) -> None:
         source = "Orangutan has %d banana.\n"
         target = [

weblate/trans/tests/test_models.py

@@ -27,6 +27,7 @@
 from weblate.trans.models import (
     Announcement,
     AutoComponentList,
+    Category,
     Change,
     Comment,
     Component,
@@ -57,7 +58,7 @@
     STATE_READONLY,
     STATE_TRANSLATED,
 )
-from weblate.utils.stats import GlobalStats
+from weblate.utils.stats import CategoryLanguage, GlobalStats, ProjectLanguage
 from weblate.utils.version import GIT_VERSION
 
 
@@ -1065,6 +1066,51 @@ def test_order_by_request(self) -> None:
         ).order_by_request({"sort_by": "position,timestamp"}, None)
         self.assertEqual(multiple_ordered_unit.count(), 4)
 
+    def test_order_by_request_language_scope_orders_by_component(self) -> None:
+        category = Category.objects.create(
+            name="Docs", slug="docs", project=self.component.project
+        )
+        Component.objects.filter(pk=self.component.pk).update(
+            category=category, priority=120
+        )
+        high_component = self.create_po(
+            category=category,
+            name="High",
+            priority=80,
+            project=self.component.project,
+        )
+        language = Language.objects.get(code="cs")
+        high_translation = high_component.translation_set.get(language=language)
+        high_units = list(high_translation.unit_set.order_by("position"))
+        low_units = list(
+            self.component.translation_set.get(language=language).unit_set.order_by(
+                "position"
+            )
+        )
+        high_priority_unit = high_units[-1]
+        Unit.objects.filter(pk=high_priority_unit.pk).update(priority=200)
+
+        expected_ids = [
+            high_priority_unit.pk,
+            *(unit.pk for unit in high_units if unit.pk != high_priority_unit.pk),
+            *(unit.pk for unit in low_units),
+        ]
+
+        scopes = [
+            ProjectLanguage(self.component.project, language),
+            CategoryLanguage(category, language),
+        ]
+        for scope in scopes:
+            ordered_ids = list(
+                Unit.objects.filter(
+                    translation__component__in=(self.component, high_component),
+                    translation__language=language,
+                )
+                .order_by_request({}, scope)
+                .values_list("pk", flat=True)
+            )
+            self.assertEqual(ordered_ids, expected_ids)
+
     def test_get_max_length_no_pk(self) -> None:
         unit = Unit.objects.filter(translation__language_code="cs")[0]
         unit.pk = False

weblate/trans/views/edit.py

@@ -621,6 +621,37 @@ def handle_suggestions(
     return HttpResponseRedirect(redirect_url)
 
 
+def handle_component_shift_notice(
+    request: AuthenticatedHttpRequest, unit_set, search_result, unit
+) -> None:
+    """Show a warning when sequential navigation moves to another component."""
+    last_viewed_unit_id = search_result.get("last_viewed_unit_id")
+    if last_viewed_unit_id:
+        try:
+            previous_unit = unit_set.get(pk=last_viewed_unit_id)
+        except Unit.DoesNotExist:
+            previous_unit = None
+        if (
+            previous_unit is not None
+            and unit.translation.component != previous_unit.translation.component
+        ):
+            messages.warning(
+                request,
+                gettext("You have shifted from %(previous)s to %(current)s.")
+                % {
+                    "previous": previous_unit.translation.full_slug,
+                    "current": unit.translation.full_slug,
+                },
+            )
+
+    search_result["last_viewed_unit_id"] = unit.id
+    session_key = search_result["key"]
+    if session_key in request.session:
+        session_result = request.session[session_key]
+        session_result["last_viewed_unit_id"] = unit.id
+        request.session[session_key] = session_result
+
+
 @transaction.atomic
 def translate(request: AuthenticatedHttpRequest, path):
     """Translate, suggest and search view."""
@@ -675,19 +706,7 @@ def translate(request: AuthenticatedHttpRequest, path):
             messages.error(request, gettext("Invalid search string!"))
             return redirect(obj)
 
-    last_viewed_unit_id = search_result.get("last_viewed_unit_id")
-    if last_viewed_unit_id:
-        previous_unit = unit_set.get(pk=last_viewed_unit_id)
-        if unit.translation.component != previous_unit.translation.component:
-            messages.warning(
-                request,
-                gettext("You have shifted from %(previous)s to %(current)s.")
-                % {
-                    "previous": previous_unit.translation.full_slug,
-                    "current": unit.translation.full_slug,
-                },
-            )
-    search_result["last_viewed_unit_id"] = unit.id
+    handle_component_shift_notice(request, unit_set, search_result, unit)
 
     # Some URLs we will most likely use
     base_unit_url = f"{obj.get_translate_url()}?{search_result['url']}&offset="