- Fix zstd compression in ab mode (PR [833](https://github.com/piskvorky/smart_open/pull/833), [ddelange](https://github.com/ddelange))
- Fix close function not neing able to upload a compressed S3 (PR [838](https://github.com/piskvorky/smart_open/pull/838), [jbarragan-bridge](https://github.com/jbarragan-bridge))
- Fix test_http.request_callback (PR [828](https://github.com/piskvorky/smart_open/pull/828), [ddelange](https://github.com/ddelange))
- Update readline logic for azure to match s3 (PR [826](https://github.com/piskvorky/smart_open/pull/826), [quantumfusion](https://github.com/quantumfusion))
- Make http handler take an optional requests.Session (PR [825](https://github.com/piskvorky/smart_open/pull/825), [arondaniel](https://github.com/arondaniel))
- Ensure no side effects on SinglepartWriter exception (PR [820](https://github.com/piskvorky/smart_open/pull/820), [donsokolone](https://github.com/donsokolone))
- Add support for `get_blob_kwargs` to GCS blob read operations (PR [817](https://github.com/piskvorky/smart_open/pull/817), [thejcannon](https://github.com/thejcannon))