This is necessary for ZFS systems, which don't support UF_IMMUTABLE.

(Note: this commit is a manual merge of 78699:019a2390b014 as both
_test_chflags_regular_file and test_lchflags_symlink differ between
3.2 and default.)

This is necessary for ZFS systems, which don't support UF_IMMUTABLE.

Patch by Ethan Furman.

Patch by Ethan Furman.

Suggestion and patch by Mike Hoy.

Suggestion and patch by Mike Hoy.

Patch by Robin Schreiber.

Patch by Robin Schreiber.

Found by Coverity.

Break up the 'someos' docs classification based on a more user-focused scheme, including creation of a separate 'Concurrent Execution' section

s/path importer/path based finder/ (because the path based finder is not an importer and the simpler 'path finder' is too ambiguous)

Close #14814: Avoid depending on struct by using newer features. Also use enumerate where appropriate (patch by Serhiy Storchaka). Declaring PEP 3144 final at this point - any further changes to code or docs can go in new issues.

Issue #14814: document the Interface APIs and fix various problems with the string representations (initial patch by Eli Bendersky).

Patch by Francisco Martín Brugué.

Patch by Francisco Martín Brugué.