diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -2089,7 +2089,7 @@ def merge(ui, repo, node=None, **opts):
         roots, heads = [common.node()], [p2.node()]
         displayer = cmdutil.show_changeset(ui, repo, opts)
         for node in repo.changelog.nodesbetween(roots=roots, heads=heads)[0]:
-        	displayer.show(repo[node])
+            displayer.show(repo[node])
         return 0
 
     return hg.merge(repo, node, force=opts.get('force'))