GeezerVison

GH-95498

Document the behavior of open() when passed an existing file descriptor.

When an existing file descriptor is passed to open(), its underlying access mode is not changed. The caller is responsible for ensuring that the file descriptor is compatible with the requested mode.

This is a resubmission of the documentation change from #159324. The earlier PR was closed while the PSF Individual Contributor Agreement was unsigned; the CLA has now been signed for the commit author email, and the CLA bot confirms all commit authors have signed.

Tests

• git diff --check passed.
• The local documentation build could not be completed because of an issue with the local documentation tooling environment.