fix deltas of tool_call.name

Author: ochafik

common/chat.cpp

@@ -101,9 +101,9 @@ std::vector<common_chat_msg_diff> common_chat_msg_diff::compute_diffs(const comm
         if (!args_diff.empty() || pref.id != newf.id) {
             auto & diff = diffs.emplace_back();
             diff.tool_call_index = idx;
-            diff.tool_call_delta.name = newf.name;
             if (pref.id != newf.id) {
                 diff.tool_call_delta.id = newf.id;
+                diff.tool_call_delta.name = newf.name;
             }
             diff.tool_call_delta.arguments = args_diff;
         }

tools/server/tests/utils.py

@@ -341,7 +341,7 @@ def make_any_request(
                         tool_call['id'] = tc['id']
                     fct = tc['function']
                     if fct.get('name') is not None:
-                        tool_call['function']['name'] = fct['name']
+                        tool_call['function']['name'] = tool_call['function'].get('name', '') + fct['name']
                     if fct.get('arguments') is not None:
                         assert len(fct['arguments']) > 0, f'Expected non empty arguments delta!'
                         tool_call['function']['arguments'] += fct['arguments']