`.get(b"split_names", None).decode()` was called unconditionally in both
Permutations.__init__ and Permutation.from_tables(), crashing with
AttributeError when schema metadata existed but lacked the split_names
key. Guard the decode behind a None check and add regression tests.
url_retrieve() calls urllib.request.urlopen() but only urllib.error was
imported, causing AttributeError for any HTTP URL input. This affects
open-clip, siglip, and jinaai embedding functions when processing image
URLs.
The bug has existed since the embeddings API refactor (#580) but was
masked because most users pass local file paths or bytes rather than
HTTP URLs.
dict.update() mutates in place and returns None. Assigning its result
caused with_metadata(None) to strip all schema metadata when embedding
metadata was merged during create_table with embedding_functions.
Replace ~30 production `lock().unwrap()` calls that would cascade-panic
on a poisoned Mutex. Functions returning `Result` now propagate the
poison as an error via `?` (leveraging the existing `From<PoisonError>`
impl). Functions without a `Result` return recover via
`unwrap_or_else(|e| e.into_inner())`, which is safe because the guarded
data (counters, caches, RNG state) remains logically valid after a
panic.
lennylxx