Bug fix for APISearchView (#12707)

The global search endpoint dispatches to viewset-based result types using a bare HttpRequest() with an empty META, so pagination's build_absolute_uri() crashes on the missing SERVER_NAME.

src/backend/InvenTree/InvenTree/api.py

@@ -873,6 +873,14 @@ class APISearchView(GenericAPIView):
                         req.user = request.user
                         req.GET = params
 
+                        # Copy META from the original request, so that host/scheme
+                        # information is available (e.g. for pagination links).
+                        # Strip content-length/type, as this is a synthetic GET
+                        # request with no body of its own to parse.
+                        req.META = request.META.copy()
+                        req.META.pop('CONTENT_LENGTH', None)
+                        req.META.pop('CONTENT_TYPE', None)
+
                         list_method = cls.as_view({'get': 'list'})(req, *args, **kwargs)
                     else:
                         list_method = view.list(request, *args, **kwargs)

src/backend/InvenTree/InvenTree/test_api.py

@@ -333,6 +333,26 @@ class SearchTests(InvenTreeAPITestCase):
             response = self.post(reverse('api-search'), d, expected_code=400)
             self.assertIn('Search term must be provided', str(response.data))
 
+    def test_viewset_pagination(self):
+        """Test that a paginated 'next' link can be constructed for viewset-backed result types.
+
+        Regression test: the search endpoint dispatches to viewset-based result types
+        (e.g. PurchaseOrderViewSet) using a synthetic request object. If that request
+        is missing WSGI environ data (e.g. SERVER_NAME), pagination raises a KeyError
+        when building the 'next' link.
+        """
+        self.assignRole('purchase_order.view')
+
+        response = self.post(
+            reverse('api-search'),
+            {'search': 'PO', 'limit': 2, 'purchaseorder': {}},
+            expected_code=200,
+        )
+
+        result = response.data['purchaseorder']
+        self.assertGreater(result['count'], 2)
+        self.assertIsNotNone(result['next'])
+
     def test_results(self):
         """Test individual result types."""
         response = self.post(