548c882d47
`buildInfo` has always reported 4.4.0 and the handshake has always reported maxWireVersion 8, which is 4.2. A driver believes the wire version: it refused client-side to send `hint` on an unacknowledged delete or findAndModify (the error is "only supported on MongoDB 4.4+", raised without a round trip), and withheld `comment` from getMore, listCollections and listDatabases (lib/operations/get_more.js:43 and its neighbours). Both are things this engine handles -- the acknowledged hint suites pass, and getMore ignores fields it does not know -- so the effect was purely the number disagreeing with itself. The 8 was not arbitrary. The comment above it tied it to omitting `topologyVersion`, which is what keeps a driver off the streaming hello protocol we do not implement -- a real bug, once visible as Compass reconnecting every heartbeat. Checked before touching it, in the driver rather than from memory: `useStreamingProtocol` (lib/sdam/monitor.js:154) returns false whenever `topologyVersion` is absent and never looks at the wire version at all. The omission is the whole mechanism; the wire version was a second line of defence that never existed. The comment now says so. A test asserts the two agree, so they cannot drift apart again silently, which is the actual defect here -- not the value. Spec suites 173/118/196 -> 189/102/196: 16 cases fixed, none broken. Ten are the unacknowledged-hint cases the previous commit uncovered, six are `comment` forwarding. 166/166 unit tests in ReleaseFast and ReleaseSafe, 82/82 fuzz, e2e 49, e2e2 concurrent 2 + crash pair, e2e3 16, e2e4 17, e2e6 72, e2e7 86, crash-fuzz 60 cycles.
36 KiB
36 KiB