histedit: sniff-test for untracked file conflicts before prompting for rules
This bug is as old as histedit, which is more than 10 years! I'm a
little sad about the extra calculations here that we're just going to
throw out, but I don't see any better way to look for untracked file
conflicts and I want the bug fixed.
Differential Revision: https://phab.mercurial-scm.org/D6882
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}