fix: remove duplicate import and guard empty-string mapping for None tool names

- Remove the duplicate `restore_openai_tool_name_for_user` import in
  streaming_chunk_builder_utils.py
- Only store the sanitized→original name mapping when the original name
  is non-empty; when `fn["name"]` is None the generated placeholder
  (e.g. `litellm_unnamed_tool_0`) is kept as-is on the response path
  instead of being replaced with an empty string

Co-authored-by: Cursor <cursoragent@cursor.com>

litellm/litellm_core_utils/streaming_chunk_builder_utils.py

@@ -9,9 +9,6 @@ from litellm.types.llms.openai import (
     ChatCompletionAssistantContentValue,
     ChatCompletionAudioDelta,
 )
-from litellm.litellm_core_utils.openai_tool_name_mapping import (
-    restore_openai_tool_name_for_user,
-)
 from litellm.types.utils import (
     ChatCompletionAudioResponse,
     ChatCompletionMessageToolCall,

litellm/utils.py

@@ -7918,13 +7918,13 @@ def _maybe_fix_openai_function_tool_name(
     if tool_type is not None and tool_type != "function":
         return
     raw = fn.get("name")
-    raw_original = str(raw) if raw is not None else ""
+    raw_original = str(raw) if raw is not None else None
     base = _sanitize_openai_function_tool_name(
         str(raw) if raw is not None else "", index
     )
     unique = _make_unique_openai_tool_name(base, used_names)
     fn["name"] = unique
-    if unique != raw_original:
+    if raw_original and unique != raw_original:
         store_openai_tool_name_mapping(unique, raw_original)