templatekw: allow accessing to nested namespace item by its template name

Since we have the dot operator, it makes more sense to write

  {namespaces.tags % "{tag}"}

instead of

  {namespaces.tags % "{name}"}

mercurial/templatekw.py

@@ -618,9 +618,14 b' def shownamespaces(**args):'
     repo = ctx.repo()
 
     namespaces = util.sortdict()
+    def makensmapfn(ns):
+        # 'name' for iterating over namespaces, templatename for local reference
+        return lambda v: {'name': v, ns.templatename: v}
 
     for k, ns in repo.names.iteritems():
-        namespaces[k] = showlist('name', ns.names(repo, ctx.node()), args)
+        names = ns.names(repo, ctx.node())
+        f = _showlist('name', names, args)
+        namespaces[k] = _hybrid(f, names, makensmapfn(ns), pycompat.identity)
 
     f = _showlist('namespace', list(namespaces), args)
 

tests/test-command-template.t

@@ -4130,6 +4130,9 b' Test namespaces dict'
   $ hg log -r2 -T '{get(namespaces, "bookmarks") % "{name}\n"}'
   bar
   foo
+  $ hg log -r2 -T '{namespaces.bookmarks % "{bookmark}\n"}'
+  bar
+  foo
 
 Test stringify on sub expressions