[dajiaohuang]

Summary

AppiumConnection.get_remote_connection_headers() currently stores each new-session X-Idempotency-Key in the class-level extra_headers dictionary. Concurrent session creation can overwrite that shared value before headers are returned, giving separate /session requests the same idempotency key. Keep the per-request key in a local copy while preserving the existing custom-header cleanup behavior for non-session requests.

Adds a deterministic barrier-based unit regression test that forces two synthetic /session header builds to overlap and checks the keys remain distinct.

Validation

• uv run --no-sync pytest -q test/unit/webdriver/appium_connection_test.py — passed.
• uv run --no-sync pytest -q test/unit — passed on Windows, Python 3.13.8.
• Ruff check and format check on both changed files — passed.
• No Appium server, real device, application, or remote account was used.

The change and regression test were prepared with AI assistance and validated locally by the contributor.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: dajiaohuang / name: dajiaohuang (1a468fd)

[KazuCocoa]

Please sign the CLA

[dajiaohuang]

/easycla