From b11a93df41921846a10628a7c306d5c82a549939 Mon Sep 17 00:00:00 2001
From: Xuan Son Nguyen <thichthat@gmail.com>
Date: Mon, 26 Feb 2024 23:15:48 +0100
Subject: [PATCH] fix server hangs on empty prompt (#5733)

---
 examples/server/server.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/examples/server/server.cpp b/examples/server/server.cpp
index 8aadc95a9728f..846ef7e5fee4f 100644
--- 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);
         }
     }