Rebuild the exact-entry reviewedCompatibilityExceptions carve-out in the
base-owned schema-compat checker for the three destructive batch-remove
tools whose confirmation PR #1085 tightens from not_required to
user_required (doc/doc.remove_permission, drive/drive.permission_remove,
wiki/wiki.remove_member). Because the compatibility gate builds its
checker from the PR merge-base, this carve-out has to land on main before
PR #1085 can pass; the entry set is exact (tool + field + old -> new), so
any other confirmation drift, including weakening a reviewed tool back to
not_required, still fails.
A stamp-shaped directory name is not ownership proof: pruneSkillBackups
counted and RemoveAll'd any 20260819-120000-shaped entry under
~/.dws/skill-backups, so a user or tool that created such a directory
lost its contents once DWS held five backups, and the Go backup path
(MkdirAll) adopted a same-named foreign root outright. The PowerShell
installers already implemented the correct contract; every other
surface now matches it.
Go stamps a freshly created root with the exact marker bytes the
install scripts write (.dws-skill-backup = "dws skill backup v1")
before any payload moves in, claims the root with mkdir so an existing
unproven root bumps to a collision suffix instead of being adopted,
and prunes only roots whose marker verifies — unmarked or wrongly
worded stamp-shaped directories are foreign data, preserved and never
counted against the keep limit. The shell installers (install.sh,
install-skills.sh, install-event.sh, install-devapp.sh) and the npm
installer apply the same rule in their backup collision loops, with
roots recorded as created by the running process exempt from marker
re-verification so a mid-run marker permission failure still reuses
this run's own root and keeps the sibling payload intact.
Regression tests cover every surface: pruning an unmarked/wrongly
marked stamp-shaped directory alongside marked ones, refusing to adopt
a foreign root (payload moves to a suffixed root, foreign data and its
nonexistent marker untouched), same-stamp reuse of a proven root, and
marker-write failure cleaning the empty fresh root.
copy_tree published staged children with mv, which replaces a
concurrently created same-name directory (POSIX rename succeeds over an
empty target) and whose rollback moved every dest child back — including
a concurrent writer's different-named entries — before deleting the
staging tree. Children now publish through kernel-level no-clobber
primitives (mkdir claim + recursion for directories with the recorded
mode restored, ln for regular files, ln -s for symlinks), a manifest
records exactly what this transaction published, the rollback retracts
only those entries in reverse order, and each level re-counts the
destination so a foreign different-named entry aborts the publish with
the destination retained. Read-only staged directories (0555 skill
trees) are made owner-writable for the move; the backup restore uses the
same discipline so a concurrent writer is refused without partially
draining the backup.
Regression tests cover both scripts: a concurrently created same-name
empty child directory and a different-named foreign entry mid-publish
are retained with the original backup kept; both fail against the
previous mv-based implementation.
Linux overlayfs recycles device+inode, so SameFile and a lone inode
token treated a replacement as owned and retracted it. Stamp staged
inodes with an xattr mark, prove Linux/Darwin identity with birth
time, and make shell copied-set rollback check dest first with inode
plus child names.
Record dest on occupy and retract it when confirmation, verify, or
staging cleanup fails. Restore unmatched quarantine with a no-replace
publish. Event/devapp copy uses mkdir-claim; shell rollback claims dest
before delete. Release copy now says npm/PowerShell create junctions and
Go uses os.Symlink, with copy fallback when linking is unavailable.
The shell mono/multi set publishers staged each Skill directory and
published it with a plain mv after the backup; anything another process
created at the destination between the backup and the move was silently
replaced, and restore_multi_skill_set then blind-deleted manifest paths,
so a concurrently replaced object could also be destroyed during
rollback. Publish through an atomic mkdir claim instead — EEXIST refuses
any occupant, staged children move into the claim one by one, and a
failed child move relocates them and removes only the claim. The
published manifest now records <dest>:<inode>, and rollback deletes a
destination only when its inode still matches the publication, skipping
concurrently replaced paths with a warning. Also fixes a latent
unbound-variable expansion where a shell variable was followed directly
by a full-width parenthesis in a message. Regression tests publish a
first Skill, replace it with a foreign directory, fail the second
publication, and assert rollback retains the foreign object untouched
while restoring the rest from backups.
The POSIX shell installers staged shared Skill links and published them
with mv after an existence check; a file or symlink another process
created at the destination between the check and the move was silently
replaced, and the inode confirmation could not detect the loss. Publish
by creating each link directly at its destination instead — symlink(2)
refuses an occupied path with EEXIST, so the creation itself is the
atomic no-replace check. A directory that appears at the destination
turns ln -s into a container; the nested link is removed after an
identity check and the transaction rolls back, leaving the foreign
directory untouched. Applied to install.sh, install-skills.sh,
install-event.sh, and install-devapp.sh. Also covers the remaining
retraction branches of the Go shell-removal fallback so changed-code
coverage is complete. Regression tests inject a concurrent occupant at
the publish instant for regular-file and directory cases and assert the
foreign object and its contents stay completely unchanged.
Dennis