# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 1182696474 18000
# Node ID 5b2d986de0f8a3c2d5ae99e8aa52419c4971711e
# Parent  59b8f9361545aaa3565662b0c17202183769b86d
cat: return an error on failure

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -342,10 +342,13 @@ def cat(ui, repo, file1, *pats, **opts):
     %p   root-relative path name of file being printed
     """
     ctx = repo.changectx(opts['rev'])
+    err = 1
     for src, abs, rel, exact in cmdutil.walk(repo, (file1,) + pats, opts,
                                              ctx.node()):
         fp = cmdutil.make_file(repo, opts['output'], ctx.node(), pathname=abs)
         fp.write(ctx.filectx(abs).data())
+        err = 0
+    return err
 
 def clone(ui, source, dest=None, **opts):
     """make a copy of an existing repository