Mercurial: Changelog

tests: perform grep manually in test-doctest.py This test has been failing on Windows since 0af56d3ee24c introduced the `hg files` invocation. Specifically, Windows seems to be choking on special characters in the fileset pattern. I believe at least \n and > were causing issues. I attempted various incantations to make the Windows command line parser accept the fileset but couldn't get anything working. I declared bankruptcy and just reimplemented the grepping code in Python. After this change, the test now passes on Windows again. Differential Revision: https://phab.mercurial-scm.org/D8343

tests: prevent printing \r to stdout Like we've done in other recent commits, we need to change sys.stdout on Python 3 to not use os.linesep so output is consistent on Python 3 on Windows. With this change, test-notify.t now passes on Python 3 on Windows! Differential Revision: https://phab.mercurial-scm.org/D8342

tests: force \n newlines when writing to sys.stdout Without this, Python 3 on Windows inserts some \r that aren't present in the input, causing test-http-bad-server.t to fail. After this change, the test passes on Python 3 on Windows! Differential Revision: https://phab.mercurial-scm.org/D8341

dispatch: force \n for newlines on sys.std* streams (BC) The sys.std* streams behave differently on Python 3. On Python 3, these streams are an io.TextIOWrapper that wraps a binary buffer stored on a .buffer attribute. These TextIOWrapper instances normalize \n to os.linesep by default. On Windows, this means that \n is normalized to \r\n. So functions like print() which have an implicit end='\n' will actually emit \r\n for line endings. While most parts of Mercurial go through the ui.write() layer to print output, some code - notably in extensions and hooks - can use print(). If this code was using print() or otherwise writing to sys.std* on Windows, Mercurial would emit \r\n. In reality, pretty much everything on Windows reacts to \n just fine. Mercurial itself doesn't emit \r\n when going through the ui layer. Changing the sys.std* streams to not normalize line endings sounds like a scary change. But I think it is safe. It also makes Mercurial on Python 3 behave similarly to Python 2, which did not perform \r\n normalization in print() by default. .. bc:: sys.{stdout, stderr, stdin} now use \n line endings on Python 3 Differential Revision: https://phab.mercurial-scm.org/D8339

hook: move stdio redirection to context manager The old code was checking stdio redirection in a loop. This didn't make sense. The pattern is better expressed as a context manager IMO, so this commit refactors it to be one. Differential Revision: https://phab.mercurial-scm.org/D8338

pycompat: change argv conversion semantics Use of os.fsencode() to convert Python's sys.argv back to bytes was not correct because it isn't the logically inverse operation from what CPython was doing under the hood. This commit changes the logic for doing the str -> bytes conversion. This required a separate implementation for POSIX and Windows. The Windows behavior is arguably not ideal. The previous behavior on Windows was leading to failing tests, such as test-http-branchmap.t, which defines a utf-8 branch name via a command argument. Previously, Mercurial's argument parser looked to be receiving wchar_t bytes in some cases. After this commit, behavior on Windows is compatible with Python 2, where CPython did not implement `int wmain()` and Windows was performing a Unicode to ANSI conversion on the wchar_t native command line. Arguably better behavior on Windows would be for Mercurial to preserve the original Unicode sequence coming from Python and to wrap this in a bytes-like type so we can round trip safely. But, this would be new, backwards incompatible behavior. My goal for this commit was to converge Mercurial behavior on Python 3 on Windows to fix busted tests. And I believe I was successful, as this commit fixes 9 tests on my Windows machine and 14 tests in the AWS CI environment! Differential Revision: https://phab.mercurial-scm.org/D8337