Gemini's OpenAI-compatibility endpoint strictly requires the `name` field
on `role: tool` messages — it returns HTTP 400 ("Request contains an
invalid argument") when the function name is missing. OpenAI/Anthropic/
ollama tolerate the absence, so the gap stays invisible until the
conversation accumulates a tool turn and the user routes it through Gemini
(direct API or via ollama-cloud proxy).
Fix: add a `_get_tool_call_name_static()` helper alongside the existing
`_get_tool_call_id_static()`, and populate `name` at every site that
constructs a `role: tool` message — the pre-call sanitizer stub, the
tool-call args repair marker, both interrupt-skip paths, both
result-append paths (parallel + sequential), the invalid-tool-name
recovery, the invalid-JSON-args recovery, and the exception fallback.
Each call site was already in scope of the function name (`function_name`,
`skipped_name`, `name`, or a dict tool_call), so the change is local —
no new lookups, no behavior change for providers that already worked.
Fixes#16478
When a session is split by context compression mid-tool-call, an assistant
message may end up with truncated/invalid JSON in tool_calls[*].function.arguments.
On the next turn this is replayed verbatim and providers reject the entire request
with HTTP 400 invalid_tool_call_format, bricking the conversation in a loop that
cannot recover without manual session quarantine.
This patch adds a defensive sanitizer that runs immediately before
client.chat.completions.create() in AIAgent.run_conversation():
- Validates each assistant tool_calls[*].function.arguments via json.loads
- Replaces invalid/empty arguments with '{}'
- Injects a synthetic tool response (or prepends a marker to the existing one)
so downstream messages keep valid tool_call_id pairing
- Logs each repair with session_id / message_index / preview for observability
Defense in depth: corruption can originate from compression splits, manual edits,
or plugin bugs. Sanitizing at the send chokepoint catches all sources.
Adds 7 unit tests covering: truncated JSON, empty string, None, non-string args,
existing matching tool response (no duplicate injection), non-assistant messages
ignored, multiple repairs.
Fixes#15236
