Link to problem area: https://spec.matrix.org/v1.15/client-server-api/#get_matrixclientv3roomsroomidcontexteventid

Issue

limit integer
The maximum number of context events to return. The limit applies to the sum of the events_before and events_after arrays. The requested event ID is always returned in event even if limit is 0. Defaults to 10.

The limit is specified as divided between events_before and events_after, which for odd limits implies a remainder. Rust-SDK tests that this remainder is given to events_after, despite a naive implementation discarding it with two truncated integer divisions. It probably derived this idea from some other implementation, establishing a de facto specification which should be reflected here.