only save log cache if tasks events are actually found

inventory_provider/routes/jobs.py

@@ -94,8 +94,12 @@ def load_task_log():
             'failed': []
         }
 
+        found_tasks = False
         for task in monitor.load_task_log(
                 current_app.config['INVENTORY_PROVIDER_CONFIG']).values():
+
+            found_tasks = True
+
             for event in task.get('task-warning', []):
                 result['warnings'].append(event['message'])
             for event in task.get('task-error', []):
@@ -124,7 +128,7 @@ def load_task_log():
                         description = task['task-started'][0]['uuid']
                     result['pending'].append(description)
 
-        if not result['pending']:
+        if found_tasks and not result['pending']:
             r.set(cache_key, json.dumps(result))
 
     return jsonify(result)