[PATCH 2 of 2] cat: use the topmost repo when expanding node based format strings for output

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1395456880 14400
# Node ID c84cafbba40646fd586f6540599963ef3f9046f5
# Parent  3c598f1d1b79671030d3e6a550dd8727f3429eb9
cat: use the topmost repo when expanding node based format strings for output

Expanding these variables based on the top level repo makes the subrepo seem
more integrated with the parent, and is probably less surprising to a user that
executes this command from the top level repo.

This solution isn't very satisfying because it requires passing two contexts
around, and it isn't reusable in other places that may need info about the top
level context that includes the repo.  The alternate attempt I made was to store
the parent context in the subrepo class when it is initialized.  The svn and git
subrepos already do this.  That didn't work because the chain that can be
followed up to the root of hgsubrepo is based on localrepository objects, not
subrepo instances.  But at least this allows for proper behavior until something
better can be figured out.

diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -1812,11 +1812,11 @@
     forgot.extend(forget)
     return bad, forgot
 
-def cat(ui, repo, ctx, matcher, prefix, **opts):
+def cat(ui, repo, ctx, matcher, prefix, rootctx, **opts):
     err = 1
 
     def write(path):
-        fp = makefileobj(repo, opts.get('output'), ctx.node(),
+        fp = makefileobj(rootctx._repo, opts.get('output'), rootctx.node(),
                          pathname=os.path.join(prefix, path))
         data = ctx[path].data()
         if opts.get('decode'):
@@ -1857,7 +1857,7 @@
             submatch = matchmod.narrowmatcher(subpath, matcher)
 
             if not sub.cat(ui, submatch, os.path.join(prefix, sub._path),
-                           **opts):
+                           rootctx, **opts):
                 err = 0
         except error.RepoLookupError:
             ui.status(_("skipping missing subrepository: %s\n")
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1179,7 +1179,7 @@
     ctx = scmutil.revsingle(repo, opts.get('rev'))
     m = scmutil.match(ctx, (file1,) + pats, opts)
 
-    return cmdutil.cat(ui, repo, ctx, m, '', **opts)
+    return cmdutil.cat(ui, repo, ctx, m, '', ctx, **opts)
 
 @command('^clone',
     [('U', 'noupdate', None,
diff --git a/mercurial/subrepo.py b/mercurial/subrepo.py
--- a/mercurial/subrepo.py
+++ b/mercurial/subrepo.py
@@ -439,7 +439,7 @@
     def add(self, ui, match, dryrun, listsubrepos, prefix, explicitonly):
         return []
 
-    def cat(self, ui, match, prefix, **opts):
+    def cat(self, ui, match, prefix, rootctx, **opts):
         return 1
 
     def status(self, rev2, **opts):
@@ -612,10 +612,10 @@
                            os.path.join(prefix, self._path), explicitonly)
 
     @annotatesubrepoerror
-    def cat(self, ui, match, prefix, **opts):
+    def cat(self, ui, match, prefix, rootctx, **opts):
         rev = self._state[1]
         ctx = self._repo[rev]
-        return cmdutil.cat(ui, self._repo, ctx, match, prefix, **opts)
+        return cmdutil.cat(ui, self._repo, ctx, match, prefix, rootctx, **opts)
 
     @annotatesubrepoerror
     def status(self, rev2, **opts):
diff --git a/tests/test-subrepo.t b/tests/test-subrepo.t
--- a/tests/test-subrepo.t
+++ b/tests/test-subrepo.t
@@ -796,7 +796,23 @@
   test
   test
   $ mkdir -p tmp/sub/repo
+  $ hg cat --output tmp/HH_%H sub/repo/foo
+  $ hg cat --output tmp/RR_%R sub/repo/foo
+  $ hg cat --output tmp/h_%h sub/repo/foo
+  $ hg cat --output tmp/r_%r sub/repo/foo
+  $ hg cat --output tmp/%s_s sub/repo/foo
+  $ hg cat --output tmp/%d_d sub/repo/foo
   $ hg cat -r 0 --output tmp/%p_p sub/repo/foo
+  $ hg log -r . --template "{rev}: {node|short}\n"
+  1: be5eb94e7215
+  $ find tmp -type f | sort
+  tmp/HH_be5eb94e72150f9a8f9be0819fc35d935cbd2f30
+  tmp/RR_1
+  tmp/foo_s
+  tmp/h_be5eb94e7215
+  tmp/r_1
+  tmp/sub/repo/foo_p
+  tmp/sub/repo_d
   $ cat tmp/sub/repo/foo_p
   test
   $ mv sub/repo sub_