fix test-chat

Author: ochafik

common/chat-parser.cpp

@@ -160,7 +160,10 @@ std::optional<common_chat_msg_parser::find_regex_result> common_chat_msg_parser:
         return std::nullopt;
     }
     if (m.type == COMMON_REGEX_MATCH_TYPE_PARTIAL) {
-        incomplete(regex.str());
+        if (is_partial()) {
+            incomplete(regex.str());
+        }
+        return std::nullopt;
     }
     auto prelude = input_.substr(pos_, m.groups[0].begin - pos_);
     pos_ = m.groups[0].end;

common/chat.cpp

@@ -1494,6 +1494,11 @@ static void common_chat_parse_hermes_2_pro(common_chat_msg_parser & builder) {
     );
 
     if (auto res = builder.try_find_regex(open_regex)) {
+        if (res->groups[0].begin != 0 && res->groups[4].empty() && res->groups[5].empty()) {
+            // The only syntax we allow after the very start is <function=...> or <function name=...>
+            builder.add_content(builder.consume_rest());
+            return;
+        }
         GGML_ASSERT(res->prelude.empty()); // matching at_start
 
         const auto & block_start = res->groups[1];