[PATCH 2 of 2 STABLE] revset: mask specific names for named() predicate

[FUJIWARA Katsunori]

# HG changeset patch
# User FUJIWARA Katsunori <foozy at lares.dti.ne.jp>
# Date 1422968239 -32400
#      Tue Feb 03 21:57:19 2015 +0900
# Branch stable
# Node ID 244d92671cebd0b600a192f1c896b4ba598621dd
# Parent  147878ac1d02298847d5b2a0d2e06063b2fefe91
revset: mask specific names for named() predicate

Before this patch, revset predicate "tags()" and "named('tags')"
differ from each other, because the former doesn't include "tip" but
the latter does.

For equivalence, "named('tags')" shouldn't include the revision
corresponded to "tip". But just removing "tip" from the "tags"
namespace may cause unexpected failure of looking "tip" tag up in
other code paths.

To mask specific names ("tip" in this case) for "named()" predicate,
this patch introduces "revsetmasks" into "namespaces", and makes
"named()" predicate examine whether each names are masked by the
namespace, to which they belong.

diff --git a/mercurial/namespaces.py b/mercurial/namespaces.py
--- a/mercurial/namespaces.py
+++ b/mercurial/namespaces.py
@@ -41,7 +41,8 @@ class namespaces(object):
                       # i18n: column positioning for "hg log"
                       logfmt=_("tag:         %s\n"),
                       listnames=tagnames,
-                      namemap=tagnamemap, nodemap=tagnodemap)
+                      namemap=tagnamemap, nodemap=tagnodemap,
+                      revsetmasks=set(['tip']))
         self.addnamespace(n)
 
         bnames = lambda repo: repo.branchmap().keys()
@@ -126,11 +127,13 @@ class namespace(object):
                    dictionary)
       'namemap': function that takes a name and returns a list of nodes
       'nodemap': function that takes a node and returns a list of names
+      'revsetmasks': set of names to be masked for revset predicate "named()"
 
     """
 
     def __init__(self, name, templatename=None, logname=None, colorname=None,
-                 logfmt=None, listnames=None, namemap=None, nodemap=None):
+                 logfmt=None, listnames=None, namemap=None, nodemap=None,
+                 revsetmasks=None):
         """create a namespace
 
         name: the namespace to be registered (in plural form)
@@ -144,6 +147,7 @@ class namespace(object):
         listnames: function to list all names
         namemap: function that inputs a node, output name(s)
         nodemap: function that inputs a name, output node(s)
+        revsetmasks: set of names to be masked for revset predicate "named()"
 
         """
         self.name = name
@@ -168,6 +172,11 @@ class namespace(object):
             # i18n: column positioning for "hg log"
             self.logfmt = ("%s:" % self.logname).ljust(13) + "%s\n"
 
+        if revsetmasks is None:
+            self.revsetmasks = set()
+        else:
+            self.revsetmasks = revsetmasks
+
     def names(self, repo, node):
         """method that returns a (sorted) list of names in a namespace that
         match a given node"""
diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -1277,7 +1277,8 @@ def named(repo, subset, x):
     names = set()
     for ns in namespaces:
         for name in ns.listnames(repo):
-            names.update(repo[n].rev() for n in ns.nodes(repo, name))
+            if name not in ns.revsetmasks:
+                names.update(repo[n].rev() for n in ns.nodes(repo, name))
 
     names -= set([node.nullrev])
     return subset & names
diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -791,7 +791,6 @@ we can use patterns when searching for t
   6
   $ log 'named("tags")'
   6
-  9
 
 issue2437