amend: prevent '\n' in the note string
This comes from the evolve function. I'm not sure why this check was missing in
core, since it was present when the length check was added to evolve.
I didn't flag this as BC because 530b7361e3a9 mentioned this argument wasn't
added to the release notes due to no display capability, and that hasn't changed
AFAIK.
Differential Revision: https://phab.mercurial-scm.org/D6854
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.