datasource: fix get_items on wrong formula (#56980)

tests/test_datasource.py

@@ -160,6 +160,20 @@ def test_python_datasource_errors(pub, error_email, http_requests, emails, caplo
         assert logged_error.workflow_id is None
         assert logged_error.summary == "[DATASOURCE] Python data source ('2') gave a non-iterable result"
 
+    datasource = {
+        'type': 'formula',
+        'value': '[{"mairie-a-rdv", "Mairie A"}, {"mairie-b-rdv", "Mairie B"}]',
+        'record_on_errors': True,
+    }
+    assert data_sources.get_items(datasource) == []
+    if pub.is_using_postgresql():
+        assert pub.loggederror_class.count() == 3
+        logged_error = pub.loggederror_class.select()[2]
+        assert logged_error.workflow_id is None
+        assert logged_error.summary == (
+            '[DATASOURCE] Python data source (\'[{"mairie-a-rdv", "Mairie A"}, {"mairie-b-rdv", "Mairie B"}]\') gave a non usable result'
+        )
+
 
 def test_python_datasource_with_evalutils(pub):
     plain_list = [

wcs/data_sources.py

@@ -34,6 +34,7 @@ from .qommon.misc import get_variadic_url
 from .qommon.publisher import get_publisher_class
 from .qommon.storage import StorableObject
 from .qommon.template import Template
+from .qommon.templatetags.qommon import unlazy
 from .qommon.xml_storage import XmlStorableObject
 
 data_source_functions = {}
@@ -328,9 +329,17 @@ def _get_structured_items(data_source, mode=None):
                 elif len(value[0]) == 1:
                     return [{'id': x[0], 'text': x[0]} for x in value]
                 return value
-            elif isinstance(value[0], str):
+            elif isinstance(unlazy(value[0]), str):
                 return [{'id': x, 'text': x} for x in value]
-            return value
+            elif isinstance(value[0], dict):
+                return value
+            get_publisher().record_error(
+                'Python data source (%r) gave a non usable result' % data_source.get('value'),
+                context='[DATASOURCE]',
+                notify=data_source.get('notify_on_errors'),
+                record=data_source.get('record_on_errors'),
+            )
+            return []
         except Exception as exc:
             get_publisher().record_error(
                 'Failed to eval() Python data source (%r)' % data_source.get('value'),