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>
`graphify merge-chunks` concatenates agent-written `.graphify_chunk_*.json`
files with only a JSON-decode guard, so an oversized payload or a crafted
node/edge id (e.g. `../../etc/passwd`) flowed straight into the merged graph.
Route each chunk through `load_validated_semantic_fragment`, which stats the
file size BEFORE reading it (a multi-GB chunk can't blow up memory), parses the
JSON, and validates the byte/count caps + the node/edge id charset that blocks
path traversal (#825). An invalid chunk is skipped with a warning (filter
semantics; never abort). Left OUT of build_from_json/load_graph_json on purpose:
those must keep loading valid pre-existing graphs.
Also relax two over-strict checks in the shared validator that would otherwise
silently drop whole legitimate chunks (a relaxation — never a new rejection):
- file_type is no longer gated: build coerces any value via _FILE_TYPE_SYNONYMS
(unknown -> "concept", #840), so synonyms like "markdown"/"tool" the loader
maps must not fail validation.
- the id charset now allows Unicode word chars (build's normalize_id preserves
CJK/Cyrillic/accented-Latin ids); the explicit path-separator/".." check still
blocks directory escape.
Corrects the stale module docstring (the validator serves the devin skill path
and merge-chunks, not skill-opencode/codex).
