fix: stabilize knowledge compilation navigation updates (#17345)

rag/utils/infinity_conn.py

@@ -649,6 +649,22 @@ class InfinityConnection(InfinityConnectionBase):
                 if k in new_value:
                     del new_value[k]
 
+            # The Infinity Python client inspects value[0] for list values
+            # while building an update expression.  An empty list therefore
+            # raises IndexError before the request reaches Infinity.  Keep
+            # JSON and keyword-list columns clearable, but do not send empty
+            # values for other columns (for example, an empty vector returned
+            # by a partial row read).
+            for k, v in list(new_value.items()):
+                if not isinstance(v, list) or v:
+                    continue
+                if k in _JSON_LIST_FIELDS:
+                    new_value[k] = json.dumps([], ensure_ascii=False)
+                elif self.field_keyword(k):
+                    new_value[k] = ""
+                else:
+                    del new_value[k]
+
             remove_opt = {}  # "[k,new_value]": [id_to_update, ...]
             if removeValue:
                 col_to_remove = list(removeValue.keys())