[PATCH 1 of 5] revset: add test that should fail if '_aliasarg' tag is removed

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1455454010 -32400
#      Sun Feb 14 21:46:50 2016 +0900
# Node ID 52999dfc8c449e221709b537e35cdac144ace7d9
# Parent  b106317fea11feb11986aefadfbedc0f98efdf25
revset: add test that should fail if '_aliasarg' tag is removed

I'm going to refactor the alias processing functions. We need '_aliasarg' tag
to limit the scope of the alias expansion, but it wasn't covered by the test.
This patch adds the test that should fail if '_aliasarg' were 'symbol'.

This is the first half of the second part of the "template alias" series. The
whole series will consist of the following parts:

 1. make parsed template tree to be compatible with parser functions
    (1d461ee26e1b and 73d01cba5810)
 2. refactor alias processing to be less dependent on revset module
    (1/2 in this series)
 3. extract reusable component to parser module
 4. clean up it
 5. extend it to support template syntax
 6. add debugging/testing functions of template aliases
 7. add alias expansion routine to templater

diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -1799,6 +1799,27 @@ far away.
   abort: unknown revision '$1'!
   [255]
 
+test scope of alias expansion: 'universe' is expanded prior to 'shadowall(0)',
+but 'all()' should never be substituded to '0()'.
+
+  $ echo 'universe = all()' >> .hg/hgrc
+  $ echo 'shadowall(all) = all and universe' >> .hg/hgrc
+  $ try 'shadowall(0)'
+  (func
+    ('symbol', 'shadowall')
+    ('symbol', '0'))
+  * expanded:
+  (and
+    ('symbol', '0')
+    (func
+      ('symbol', 'all')
+      None))
+  * set:
+  <filteredset
+    <baseset [0]>,
+    <spanset+ 0:9>>
+  0
+
   $ echo 'injectparamasstring2 = max(_aliasarg("$1"))' >> .hg/hgrc
   $ echo 'callinjection2($1) = descendants(injectparamasstring2)' >> .hg/hgrc
   $ try 'callinjection2(2:5)'