fix server hangs on empty prompt (#5733)

diff --git a/examples/server/server.cpp b/examples/server/server.cpp
index 8aadc95a9728f7ea24252f5d9e5397984d925ee2..846ef7e5fee4f556567292118488fe343082a19c 100644 (file)
--- a/examples/server/server.cpp
+++ b/examples/server/server.cpp
@@ -1336,6 +1336,10 @@ struct llama_server_context
                 split_multiprompt_task(task_id, task);
             }
         } else {
+            // an empty prompt can make slot become buggy
+            if (task.data.contains("prompt") && task.data["prompt"].is_string() && task.data["prompt"].get<std::string>().empty()) {
+                task.data["prompt"] = " "; // add a space so that we have one token
+            }
             queue_tasks.post(task);
         }
     }