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
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.