Fix IB historical bars resubscription failure after connection loss

[Johnkhk]

Pull Request

NautilusTrader prioritizes correctness and reliability, please follow existing patterns for validation and testing.

• I have reviewed the CONTRIBUTING.md and followed the established practices

Summary

Fixes a critical bug introduced in PR #2870 where historical bar subscriptions fail to resubscribe after IB Gateway disconnects/reconnects due to a parameter
signature mismatch. The fix stores start timestamps separately from the resubscription handle to prevent TypeError during automatic resubscription, restoring
proper data flow after connection loss.

Related Issues/PRs

Fixes #3001
Related to #2870

Type of change

• Bug fix (non-breaking)
• New feature (non-breaking)
• Breaking change (impacts existing behavior)
• Documentation update
• Maintenance / chore

Breaking change details (if applicable)

N/A - This is a bug fix that restores intended behavior without changing the public API.

Documentation

• Documentation changes follow the style guide (docs/developer_guide/docs.md)

No documentation changes required (code-only fix).

Release notes

• I added a concise entry to RELEASES.md that follows the existing conventions (when applicable)

Will add after review.

Testing

Ensure new or changed logic is covered by tests.

• Affected code paths are already covered by the test suite
• I added/updated tests to cover new or changed logic

---

Technical Details

Problem:

• PR Refine subscribe_historical_bars in IB adapter #2870 passes start as a separate kwarg to _subscribe() instead of within params
• Creates functools.partial with start=<value> in kwargs
• On resubscription, the partial calls subscribe_historical_bars(start=...)
• Method signature only accepts params dict → TypeError
• Resubscription silently fails, causing data starvation

Solution:

• Store start times in separate _subscription_start_times dict (keyed by req_id)
• Pass full params dict to _subscribe() instead of individual start kwarg
• Retrieve start from stored dict when filtering bars (line 907)
• Clean up stored start time on unsubscribe

Affected versions: 1.220.0, 1.221.0+
Last working version: 1.219.0

[CLAassistant]

All committers have signed the CLA.

[faysou]

Looks almost good to me. Only one thing to do now that I'm understanding the resubscription process better with your change, could you change this line

nautilus_trader/nautilus_trader/adapters/interactive_brokers/client/market_data.py

Line 445 in d7aa529

start = params.get("start_ns")

to start = params.pop("start_ns", None). Because start_ns is meant to indicate the last stored ts_init for a bar type in the catalog and a resubscription after a disconnection shouldn't replay all bars since start_ns before the first subscription, so we should use start_ns only once then remove it from the params dict.

[faysou]

Thanks for the update, as discussed just now offline, we could improve the reconnection in IB by storing the time of disconnection and take it into account in a resubscription. This could be done in another PR. I think the PR is good to go.

[cjdsellers]

Hi @Johnkhk

Thank you for the fix with detailed explanations! 🙏