[PATCH 4 of 4] revset: avoid returning duplicates when returning ancestors

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1395874550 25200
#      Wed Mar 26 15:55:50 2014 -0700
# Node ID 81d963f466607d9425d79adfed374c360fbcb5f1
# Parent  dffaf3d15f9587d3f4e00a03cd288108c5cc78fe
revset: avoid returning duplicates when returning ancestors

Before this patch, _revancestors were giving false result when a revision was
duplicated in the input. Duplicated entry are rare but may happen when using the
`%lx` notation internally.

This series has no visible impact on the performance of the function according
to benchmark.

diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -36,17 +36,17 @@ def _revancestors(repo, revs, followfirs
             irevs, inputrev = None, None
 
         seen = set()
         while h:
             current = -heapq.heappop(h)
+            if irevs is not None and current == inputrev:
+                try:
+                    inputrev = irevs.next()
+                    heapq.heappush(h, -inputrev)
+                except StopIteration:
+                    irevs, inputrev = None, None
             if current not in seen:
-                if irevs is not None and current == inputrev:
-                    try:
-                        inputrev = irevs.next()
-                        heapq.heappush(h, -inputrev)
-                    except StopIteration:
-                        irevs, inputrev = None, None
                 seen.add(current)
                 yield current
                 for parent in cl.parentrevs(current)[:cut]:
                     if parent != node.nullrev:
                         heapq.heappush(h, -parent)
diff --git a/tests/test-revset.t b/tests/test-revset.t
--- a/tests/test-revset.t
+++ b/tests/test-revset.t
@@ -1,7 +1,29 @@
   $ HGENCODING=utf-8
   $ export HGENCODING
+  $ cat > testrevset.py << EOF
+  > import mercurial.revset
+  > 
+  > baseset = mercurial.revset.baseset
+  > 
+  > def r3232(repo, subset, x):
+  >     """"simple revset that return [3,2,3,2]
+  > 
+  >     revisions duplicated on purpose.
+  >     """
+  >     if 3 not in subset:
+  >        if 2 in subset:
+  >            return baseset([2,2])
+  >        return baseset()
+  >     return baseset([3,3,2,2])
+  > 
+  > mercurial.revset.symbols['r3232'] = r3232
+  > EOF
+  $ cat >> $HGRCPATH << EOF
+  > [extensions]
+  > testrevset=$TESTTMP/testrevset.py
+  > EOF
 
   $ try() {
   >   hg debugrevspec --debug "$@"
   > }
 
@@ -309,17 +331,26 @@ ancestor can accept 0 or more arguments
   1
   $ log 'ancestor(0,1,3,5)'
   0
   $ log 'ancestor(1,2,3,4,5)'
   1
+
+test ancestors
+
   $ log 'ancestors(5)'
   0
   1
   3
   5
   $ log 'ancestor(ancestors(5))'
   0
+  $ log '::r3232()'
+  0
+  1
+  2
+  3
+
   $ log 'author(bob)'
   2
   $ log 'author("re:bob|test")'
   0
   1