[teddiesloco]

Summary

• Fixes filesystem: a Windows-style path is silently accepted on POSIX and becomes a literal filename inside the allowed root #4686 by ensuring Windows-style drive paths on POSIX platforms do not get converted to invalid backslash formats during normalizePath.
• Preserves native path separators depending on the runtime process.platform.

Test Plan

• Verified path normalization on POSIX and Windows formatted test cases.
• Validated normalizePath('C:/Users/test') preserves forward slashes on POSIX.

[cliffhall]

Thank you for this pull request, and apologies for the long wait for a response.

Since it was opened, the reference servers have been rebuilt for the 2026-07-28 MCP specification (#4857) and released as v2 (2.0.0 on npm for the TypeScript servers, 2026.10.19 on PyPI for the Python servers). The code this PR changes has been replaced, and the behavior it addresses has either been fixed in v2 or no longer exists in the same form.

This is not a judgment on the change or on you; it's a consequence of the code it targets having been replaced. If the problem still happens on v2, please open a fresh issue with the version you're running and steps to reproduce. Note that this repository now accepts contributions as issues rather than pull requests from anyone but its maintainers; see CONTRIBUTING.md.

This is part of the backlog triage in #4875.