Update app.py

app.py

@@ -38,12 +38,13 @@ def stream_chat(message: Dict[str, str], history: list):
     # {'text': 'continue?', 'files': []}
     # [[('image-xxx.jpg',), None], ['what is this', 'a image.']]
 
+    image_path = None
     if len(message["files"]) != 0:
         image_path = message["files"][0]
 
-    if isinstance(history[0][0], tuple):
+    if len(history) != 0 and isinstance(history[0][0], tuple):
         image_path = history[0][0][0]
-        history.pop(0)
+        history = history[1:]
 
     if image_path is not None:
         image = Image.open(image_path)