* chat : reject JSON nested more than 128 levels before walking it
The schema builder, the jinja engine and the decision code walk request
JSON with recursion. A request nested deep enough overflows the stack of
the HTTP thread and llama-server dies (SIGBUS on macOS, SIGSEGV on Linux):
for a tool schema from a few hundred levels on macOS and about 10000 on
Linux.
Check the depth first and answer 400 past 128 levels: the chat inputs in
common_chat_templates_apply (tools, tool-call arguments,
chat_template_kwargs, json_schema), the json_schema of /completion, and the
whole /v1/systemone body. A gemma4 tool result that is too deep stays text.
* fix the root, not the call side
---------
Co-authored-by: Xuan Son Nguyen <son@huggingface.co>
The d1-omni and kev prompts escape "<|name|>" in the request text with
std::regex_replace. libstdc++ recurses for each char of the name, so a
state of "<|" and 30000 letters overflows the stack of the HTTP thread
and llama-server dies with SIGSEGV.
server_decision_escape_special_tokens() writes the same text with a loop.
test-server-component compares it with the regex on every string of up to
6 chars of "<|>a-".
