[PATCH 2 of 3 V2] revset: cleanup of algorithm for `destination()` predicate

[Hannes Oldenburg]

# HG changeset patch
# User Hannes Oldenburg <hannes.christian.oldenburg at gmail.com>
# Date 1473454657 0
#      Fri Sep 09 20:57:37 2016 +0000
# Node ID 05b4f301b5ade476f7f2236f7bf699a4f248297d
# Parent  aeb4ff2efd119ad5bab99f0c521ca52f71144309
revset: cleanup of algorithm for `destination()` predicate

Instead of using break to leave the inner while loop if we found a destination
or a path to an already known destination, we make the check part of the
looping condition.

diff -r aeb4ff2efd11 -r 05b4f301b5ad mercurial/revset.py
--- a/mercurial/revset.py	Fri Sep 09 20:48:18 2016 +0000
+++ b/mercurial/revset.py	Fri Sep 09 20:57:37 2016 +0000
@@ -853,8 +853,8 @@
     for r in subset:
         src = _getrevsource(repo, r)
         lineage = list()
-
-        while src is not None:
+        found = False
+        while src is not None and not found:
             lineage.append(r)
 
             # The visited lineage is a match if the current source is in the arg
@@ -863,13 +863,11 @@
             # different iteration over subset.  Likewise, if the src was already
             # selected, the current lineage can be selected without going back
             # further.
-            if src in sources or src in dests:
-                dests.update(lineage)
-                break
-
+            found = src in sources or src in dests
             r = src
             src = _getrevsource(repo, r)
-
+        if found:
+            dests.update(linage)
     return subset.filter(dests.__contains__,
                          condrepr=lambda: '<destination %r>' % sorted(dests))