--- a/mercurial/debugcommands.py	Sat Jun 10 20:03:35 2017 +0900
+++ b/mercurial/debugcommands.py	Sat Jun 10 20:14:23 2017 +0900
@@ -1901,6 +1901,7 @@
 @command('debugrevspec',
     [('', 'optimize', None,
       _('print parsed tree after optimizing (DEPRECATED)')),
+     ('', 'show-revs', True, _('print list of result revisions (default)')),
      ('s', 'show-set', None, _('print internal representation of result set')),
      ('p', 'show-stage', [],
       _('print parsed tree at the given stage'), _('NAME')),
@@ -1914,6 +1915,9 @@
     Use -p/--show-stage option to print the parsed tree at the given stages.
     Use -p all to print tree at every stage.
 
+    Use --no-show-revs option with -s or -p to print only the set
+    representation or the parsed tree respectively.
+
     Use --verify-optimized to compare the optimized result with the unoptimized
     one. Returns 1 if the optimized result differs.
     """
@@ -1989,6 +1993,8 @@
     revs = func(repo)
     if opts['show_set'] or (opts['show_set'] is None and ui.verbose):
         ui.write(("* set:\n"), smartset.prettyformat(revs), "\n")
+    if not opts['show_revs']:
+        return
     for c in revs:
         ui.write("%s\n" % c)
 

--- a/tests/test-completion.t	Sat Jun 10 20:03:35 2017 +0900
+++ b/tests/test-completion.t	Sat Jun 10 20:14:23 2017 +0900
@@ -281,7 +281,7 @@
   debugrebuildfncache: 
   debugrename: rev
   debugrevlog: changelog, manifest, dir, dump
-  debugrevspec: optimize, show-set, show-stage, no-optimized, verify-optimized
+  debugrevspec: optimize, show-revs, show-set, show-stage, no-optimized, verify-optimized
   debugsetparents: 
   debugsub: rev
   debugsuccessorssets: