Refuse a read-only destination in _atomic_replace on Windows (nt-only guard;
os.replace there raises PermissionError and the fallback would silently clobber
it), plus test-only guards: utf-8 encoding kwargs, posix-shape path assertions,
FIFO/AF_UNIX/symlink skips, and a replace-retry for AV/indexer locks. No POSIX
behavior change.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Extracts the real Step 1 bash block from the committed skill.md
artifact, substitutes INPUT_PATH the way an agent following the
instructions would, and actually runs it, so the fix is checked
against what users receive rather than the fragment source alone. One
test confirms a command substitution embedded in the substituted path
never runs, another confirms a semicolon separated command never
runs, a third confirms a legitimate path with a space in it still
resolves correctly, and a fourth confirms a nonexistent path still
fails the whole step loudly. All four were checked against the
pre fix block first, three failed as expected.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017qfdzgbA5KedGEjD1AayNh
(cherry picked from commit ad98afa9f5)
