Two reversibility defects in `crates/core/src/paths.rs`:
Defect A (multi-legacy-candidate orphan):
`resolve_app_data_dir` and `legacy_and_target_paths` short-circuited
on the first legacy candidate, allowing two reachable orphan scenarios
on Linux. With both `~/.magnotia` and `~/.local/share/magnotia` the
shim migrated only the dot-home variant, leaving the XDG legacy
invisible forever. With a stray `~/.lumotia` alongside a freshly
migrated `~/.local/share/lumotia`, the resolver kept returning the
dot-home path, orphaning the XDG target.
`legacy_and_target_paths` now returns `Vec<(legacy, target)>`,
probing every legacy variant the platform supports. The migration
driver in `src-tauri/src/lib.rs` loops over the Vec and emits
per-candidate tracing. A new `resolve_app_data_dir_strict` +
`check_target_ambiguity` API refuses to start when more than one
target candidate exists post-migration, surfacing both paths to the
user via the setup hook instead of silently picking one.
Regression tests: `migrate_handles_both_dot_home_and_xdg`,
`resolve_app_data_dir_refuses_on_multiple_targets`.
Defect B (copy_dir_recursive symlink loop on EXDEV migration):
`entry.metadata()` follows symlinks, so a directory symlink reported
is_dir==true and recursed unconditionally. A self-referential or
ancestor-targeting directory symlink would loop until the disk
filled. Switched to `entry.file_type()` (symlink-aware), re-ordered
branches so `is_symlink()` is checked first, and routed all
symlinks through symlink-creation (Unix + Windows) rather than
recursive copy.
Regression tests:
`copy_dir_recursive_does_not_loop_on_self_referential_dir_symlink`,
`copy_dir_recursive_preserves_directory_symlinks`.
14/14 paths tests green. Full workspace cargo test green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Jake
6ca94cbff0