revert: accept just -I/-X without paths or -a/-i (issue4592)

'hg revert -I foo' currently fails with

  abort: no files or directories specified
  (use --all to revert all files, or 'hg update 1' to update)

It doesn't seem intentional that -I/-X without other paths or
--all/--interactive should fail, and it doesn't seem that harmful to
allow it either, so let's just do that.

mercurial/commands.py

@@ -5511,7 +5511,8 b' def revert(ui, repo, *pats, **opts):'
 
     ctx = scmutil.revsingle(repo, opts.get('rev'))
 
-    if not pats and not (opts.get('all') or opts.get('interactive')):
+    if (not (pats or opts.get('include') or opts.get('exclude') or
+             opts.get('all') or opts.get('interactive'))):
         msg = _("no files or directories specified")
         if p2 != nullid:
             hint = _("uncommitted merge, use --all to discard all changes,"

tests/test-revert.t

@@ -201,12 +201,26 b' call `hg revert` with no file specified'
   (use --all to revert all files, or 'hg update 1' to update)
   [255]
 
+call `hg revert` with -I
+---------------------------
+
+  $ echo a >> a
+  $ hg revert -I a
+  reverting a
+
+call `hg revert` with -X
+---------------------------
+
+  $ echo a >> a
+  $ hg revert -X d
+  reverting a
+
 call `hg revert` with --all
 ---------------------------
 
   $ hg revert --all -rtip
   reverting a
-
+  $ rm *.orig
 
 Issue332: confusing message when reverting directory
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