diff -r f5b00b6e426a -r 3998c1b0828f mercurial/commands.py
--- a/mercurial/commands.py	Sat Feb 09 13:05:22 2008 -0500
+++ b/mercurial/commands.py	Thu Feb 14 11:25:30 2008 +0100
@@ -467,7 +467,7 @@
                                              ctx.node()):
         fp = cmdutil.make_file(repo, opts['output'], ctx.node(), pathname=abs)
         data = ctx.filectx(abs).data()
-        if opts['decode']:
+        if opts.get('decode'):
             data = repo.wwritedata(abs, data)
         fp.write(data)
         err = 0
@@ -2768,7 +2768,7 @@
         (cat,
          [('o', 'output', '', _('print output to file with formatted name')),
           ('r', 'rev', '', _('print the given revision')),
-          ('d', 'decode', None, _('apply any matching decode filter')),
+          ('', 'decode', None, _('apply any matching decode filter')),
          ] + walkopts,
          _('hg cat [OPTION]... FILE...')),
     "^clone":