patch: fix header.__repr__() to not have `b''` prefixes in file names Spotted by Denis Laxalde. Differential Revision: https://phab.mercurial-scm.org/D7695

cmdutil: allow native string as input to check_at_most_one_arg() We seem to always convert **opts args to use bytes as keys early on in Mercurial core, but I'm not sure we have good reason to do that, and not all extensions do that. It's therefore helpful to be able to pass in a native string to check_at_most_one_arg(). Differential Revision: https://phab.mercurial-scm.org/D7699

cmdutil: return underscore-separate name from check_at_most_one_arg() As noticed by Yuya, when I changed the function (during review) to work with underscore-separated names as input, I forgot to make sure the returned name was also underscore-separated. We don't have any cases where it matters yet, but it should still clearly be fixed. Instead of converting the hyphen-separated value we already have in `previous`, I'm changing it so we convert to the underscore-separated values to be hyphen-separated only when we need to display them. This will also help a coming change where we allow the inputs to native strings instead only bytes. Differential Revision: https://phab.mercurial-scm.org/D7698