--- a/mercurial/ui.py	Wed Apr 29 19:47:37 2015 +0900
+++ b/mercurial/ui.py	Thu Apr 30 07:46:54 2015 -0700
@@ -169,6 +169,9 @@
         if self.plain('alias'):
             for k, v in cfg.items('alias'):
                 del cfg['alias'][k]
+        if self.plain('revsetalias'):
+            for k, v in cfg.items('revsetalias'):
+                del cfg['revsetalias'][k]
 
         if trusted:
             self._tcfg.update(cfg)

--- a/tests/test-revset.t	Wed Apr 29 19:47:37 2015 +0900
+++ b/tests/test-revset.t	Thu Apr 30 07:46:54 2015 -0700
@@ -1049,6 +1049,8 @@
 
   $ echo '[revsetalias]' >> .hg/hgrc
   $ echo 'm = merge()' >> .hg/hgrc
+(revset aliases can override builtin revsets)
+  $ echo 'p2($1) = p1($1)' >> .hg/hgrc
   $ echo 'sincem = descendants(m)' >> .hg/hgrc
   $ echo 'd($1) = reverse(sort($1, date))' >> .hg/hgrc
   $ echo 'rs(ARG1, ARG2) = reverse(sort(ARG1, ARG2))' >> .hg/hgrc
@@ -1064,6 +1066,58 @@
     <fullreposet+ 0:9>>
   6
 
+  $ HGPLAIN=1 try m
+  ('symbol', 'm')
+  abort: unknown revision 'm'!
+  [255]
+
+  $ HGPLAIN=1 HGPLAINEXCEPT=revsetalias try m
+  ('symbol', 'm')
+  (func
+    ('symbol', 'merge')
+    None)
+  * set:
+  <filteredset
+    <fullreposet+ 0:9>>
+  6
+
+(for some reason HGPLAIN and HGPLAINEXCEPT can carry forward)
+
+  $ unset HGPLAIN
+  $ unset HGPLAINEXCEPT
+
+  $ try 'p2(.)'
+  (func
+    ('symbol', 'p2')
+    ('symbol', '.'))
+  (func
+    ('symbol', 'p1')
+    ('symbol', '.'))
+  * set:
+  <baseset+ [8]>
+  8
+
+  $ HGPLAIN=1 try 'p2(.)'
+  (func
+    ('symbol', 'p2')
+    ('symbol', '.'))
+  * set:
+  <baseset+ []>
+
+  $ HGPLAIN=1 HGPLAINEXCEPT=revsetalias try 'p2(.)'
+  (func
+    ('symbol', 'p2')
+    ('symbol', '.'))
+  (func
+    ('symbol', 'p1')
+    ('symbol', '.'))
+  * set:
+  <baseset+ [8]>
+  8
+
+  $ unset HGPLAIN
+  $ unset HGPLAINEXCEPT
+
 test alias recursion
 
   $ try sincem