uncommit: simplify condition for keeping commit

We used to keep the commit if it would have become empty and --keep
was not passed. Since we just changed it so we also keep it if any
patterns were passed on the command line, the only remaining case
where we prune the commit is when no arguments were passed and --keep
was not passed either, we can simplify the "not files and not
allowempty" to just "not allowempty". Let's also rename "allowempty"
to "keepcommit" since it's no longer about allowing an empty commit.

Differential Revision: https://phab.mercurial-scm.org/D2891

hgext/uncommit.py

@@ -51,7 +51,7 configitem('experimental', 'uncommitondi
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
-def _commitfiltered(repo, ctx, match, allowempty):
+def _commitfiltered(repo, ctx, match, keepcommit):
     """Recommit ctx with changed files not in match. Return the new
     node identifier, or None if nothing changed.
     """
@@ -66,7 +66,7 def _commitfiltered(repo, ctx, match, al
 
     files = (initialfiles - exclude)
     # return the p1 so that we don't create an obsmarker later
-    if not files and not allowempty:
+    if not keepcommit:
         return ctx.parents()[0].node()
 
     # Filter copies
@@ -169,8 +169,8 def uncommit(ui, repo, *pats, **opts):
 
         with repo.transaction('uncommit'):
             match = scmutil.match(old, pats, opts)
-            allowempty = opts.get('keep') or pats
-            newid = _commitfiltered(repo, old, match, allowempty)
+            keepcommit = opts.get('keep') or pats
+            newid = _commitfiltered(repo, old, match, keepcommit)
             if newid is None:
                 ui.status(_("nothing to uncommit\n"))
                 return 1