[issue35928] socket makefile read-write discards received data

Change by Zackery Spytz : -- nosy: +ZackerySpytz nosy_count: 5.0 -> 6.0 pull_requests: +21538 pull_request: https://github.com/python/cpython/pull/22535 ___ Python tracker ___

[issue35928] socket makefile read-write discards received data

nr added the comment: Added PR 11878, this will pass both this bug report and PR 3918 regression, the commit Ammar noted, it is an addition to this change. -- nosy: +nr ___ Python tracker

[issue35928] socket makefile read-write discards received data

Change by nr : -- keywords: +patch pull_requests: +11912 stage: needs patch -> patch review ___ Python tracker ___ ___

[issue35928] socket makefile read-write discards received data

Ammar Askar added the comment: Recreatable on master as well, also Martin your suspicion seems correct, reverting https://github.com/python/cpython/commit/23db935bcf258657682e66464bf8512def8af830 fixes it. -- nosy: +ammar2, serhiy.storchaka stage: -> needs patch versions: +Python

[issue35928] socket makefile read-write discards received data

Palle Ravn added the comment: >>> f = TextIOWrapper(BufferedRWPair(BytesIO(b"Hello\nYou\n"), BytesIO())) >>> f.readline() 'Hello\n' >>> f.write(_) 6 >>> f.readline() # Returns empty string '' -- ___ Python tracker

[issue35928] socket makefile read-write discards received data

Martin Panter added the comment: Looking over the changelog, my guess (untested) is this is caused by commit d6a283b3 for Issue 25862. That change looks like it drops the internal TextIOWrapper decoding buffer for each successful write. I don't have the right version of Python to test with,

[issue35928] socket makefile read-write discards received data

New submission from Palle Ravn : Using socket.makefile in read-write mode had a bug introduced between version 3.6.6 and 3.6.7. The same bug is present in version 3.7.x. The below code example will behave very differently between 3.6.6 and 3.6.7. It's based on the echo-server example from