# HG changeset patch
# User Benoit Boissinot <benoit.boissinot@ens-lyon.org>
# Date 1133874638 -3600
# Node ID 63799b01985c75b4583227de7cf92757ac4300c5
# Parent  1d7d0c07e8f38005e779adb41eda042251c0c40c
fix the cat command

- improve localrepo.walk when passed a node
- make the differents walk commands in commands.py accept a node
- change commands.cat to walk over a revision
- add a test


diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -42,16 +42,16 @@ def matchpats(repo, pats=[], opts={}, he
     return util.cmdmatcher(repo.root, cwd, pats or ['.'], opts.get('include'),
                         opts.get('exclude'), head) + (cwd,)
 
-def makewalk(repo, pats, opts, head=''):
+def makewalk(repo, pats, opts, node=None, head=''):
     files, matchfn, anypats, cwd = matchpats(repo, pats, opts, head)
     exact = dict(zip(files, files))
     def walk():
-        for src, fn in repo.walk(files=files, match=matchfn):
+        for src, fn in repo.walk(node=node, files=files, match=matchfn):
             yield src, fn, util.pathto(cwd, fn), fn in exact
     return files, matchfn, walk()
 
-def walk(repo, pats, opts, head=''):
-    files, matchfn, results = makewalk(repo, pats, opts, head)
+def walk(repo, pats, opts, node=None, head=''):
+    files, matchfn, results = makewalk(repo, pats, opts, node, head)
     for r in results:
         yield r
 
@@ -634,20 +634,14 @@ def cat(ui, repo, file1, *pats, **opts):
     mf = {}
     rev = opts['rev']
     if rev:
-        change = repo.changelog.read(repo.lookup(rev))
-        mf = repo.manifest.read(change[0])
-    for src, abs, rel, exact in walk(repo, (file1,) + pats, opts):
+        node = repo.lookup(rev)
+    else:
+        node = repo.changelog.tip()
+    change = repo.changelog.read(node)
+    mf = repo.manifest.read(change[0])
+    for src, abs, rel, exact in walk(repo, (file1,) + pats, opts, node):
         r = repo.file(abs)
-        if rev:
-            try:
-                n = mf[abs]
-            except (hg.RepoError, KeyError):
-                try:
-                    n = r.lookup(rev)
-                except KeyError, inst:
-                    raise util.Abort(_('cannot find file %s in rev %s'), rel, rev)
-        else:
-            n = r.tip()
+        n = mf[abs]
         fp = make_file(repo, r, opts['output'], node=n, pathname=abs)
         fp.write(r.read(n))
 
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -462,8 +462,14 @@ class localrepository(object):
 
     def walk(self, node=None, files=[], match=util.always):
         if node:
+            fdict = dict.fromkeys(files)
             for fn in self.manifest.read(self.changelog.read(node)[0]):
-                if match(fn): yield 'm', fn
+                fdict.pop(fn, None)
+                if match(fn):
+                    yield 'm', fn
+            for fn in fdict:
+                self.ui.warn(_('%s: No such file in rev %s\n') % (
+                    util.pathto(self.getcwd(), fn), short(node)))
         else:
             for src, fn in self.dirstate.walk(files, match):
                 yield src, fn
diff --git a/tests/test-cat b/tests/test-cat
new file mode 100755
--- /dev/null
+++ b/tests/test-cat
@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+mkdir t
+cd t
+hg init
+echo 0 > a
+echo 0 > b
+hg ci -A -m m -d "0 0"
+hg rm a
+hg cat a
+sleep 1 # make sure mtime is changed
+echo 1 > b
+hg ci -m m -d "0 0"
+echo 2 > b
+hg cat -r 0 a
+hg cat -r 0 b
+hg cat -r 1 a
+hg cat -r 1 b
diff --git a/tests/test-cat.out b/tests/test-cat.out
new file mode 100644
--- /dev/null
+++ b/tests/test-cat.out
@@ -0,0 +1,7 @@
+adding a
+adding b
+0
+0
+0
+a: No such file in rev 551e7cb14b32
+1