secantus-mdb 0.5.3-beta.176 stops dropIndexes from dropping the _id index

Summary: secantus-mdb 0.5.3-beta.176 and 0.5.3-beta.175 fix a run of wrong answers on capped collections, views, document validation and indexes, each found by running the same commands against mongod 8.2.11.

If you run secantusd-rs 0.5.3-beta.174 or earlier, upgrade. The two releases since then fix places where the server answered without an error and the answer was wrong. We found them by sending the same commands to the server and to mongod 8.2.11 and comparing every reply.

The one to know about first: dropIndexes with the key {_id: 1} dropped the _id index.

db.command("dropIndexes", "orders", index={"_id": 1})

mongod refuses that with cannot drop _id index, by name, by key or in a list of names. So does 0.5.3-beta.176.

The rest, by area. Each line is something that used to succeed silently.

Inserts and validation (0.5.3-beta.176). When one document in an ordered insert_many failed the collection's validator, none of the batch was inserted. mongod inserts the documents before the failing one and stops there, and so does the server now. create and collMod refuse a validationLevel or validationAction they do not know, where they used to store it and then act as if it were the default.

Indexes (0.5.3-beta.176). createIndexes checks every spec before it builds anything. It used to accept a key value of 0, an empty field name, a negative TTL, an unknown option and nine other invalid specs, and build an index from each. unique: 1 builds a unique index; a number was read as "not unique". A hidden index is no longer used by queries, sorts or hints; the server recorded hidden and went on using the index.

Geo (0.5.3-beta.176). $geoWithin with $box, $polygon or a GeoJSON polygon left out any point lying exactly on the boundary. mongod includes those points.

Capped collections (0.5.3-beta.175). One insert_many could take a capped collection past its cap: five documents into a max: 3 collection left five. Upserts were never held to the cap at all. max: 0, which means "no limit", was read as a limit of zero, so every insert evicted everything except the newest document.

Views (0.5.3-beta.175). An insert, update or delete aimed at a view was acknowledged. distinct on a view returned nothing, $lookup from a view matched nothing, and collMod of a view's pipeline answered ok and changed nothing.

Aggregation (0.5.3-beta.175). $count over no documents returned {n: 0}. mongod returns no document, which matters inside a $lookup or $facet that counts no match.

What these releases do not do: convertToCapped is still not implemented, there is no system.views collection, and text and hashed indexes are still refused.

We ran the thirteen driver test suites against the 0.5.3-beta.176 code. Every one gave the same result as the day before, test for test. None of these bugs was in a path the drivers' own suites exercise, which is why comparing against mongod directly found them and the suites had not.

This is a server for tests. It is single-node and it is a beta.

cargo install secantus-mdb --version 0.5.3-beta.176 builds it from crates.io. Binaries for Linux x86_64, macOS arm64 and Windows x86_64 are on the release.

Rust MongoDB server · secantus-mdb on crates.io · MongoDB binaries