From e68b1cacd077f49bafa84b95103945b19910993c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Neuh=C3=A4user?= <ich@danielneuhaeuser.de>
Date: Sun, 15 Aug 2010 21:25:31 +0200
Subject: [PATCH] Optimized merging algorithm

---
 sphinx/versioning.py     | 14 ++++++++++----
 tests/test_versioning.py | 14 +-------------
 2 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/sphinx/versioning.py b/sphinx/versioning.py
index 753629042..5f3254554 100644
--- a/sphinx/versioning.py
+++ b/sphinx/versioning.py
@@ -45,11 +45,17 @@ def merge_doctrees(old, new, condition):
     old_nodes = old.traverse(condition)
     new_nodes = new.traverse(condition)
     ratios = defaultdict(list)
-    for old_node, new_node in product(old_nodes, new_nodes):
-        ratios[old_node, new_node] = get_ratio(old_node.rawsource,
-                                               new_node.rawsource)
-    ratios = sorted(ratios.iteritems(), key=itemgetter(1))
     seen = set()
+    for old_node, new_node in product(old_nodes, new_nodes):
+        if new_node in seen:
+            continue
+        ratio = get_ratio(old_node.rawsource, new_node.rawsource)
+        if ratio == 0:
+            new_node.uid = old_node.uid
+            seen.add(new_node)
+        else:
+            ratios[old_node, new_node] = ratio
+    ratios = sorted(ratios.iteritems(), key=itemgetter(1))
     for (old_node, new_node), ratio in ratios:
         if new_node in seen:
             continue
diff --git a/tests/test_versioning.py b/tests/test_versioning.py
index 5c31f0c32..06c4ff2f1 100644
--- a/tests/test_versioning.py
+++ b/tests/test_versioning.py
@@ -16,7 +16,7 @@ from docutils.statemachine import ViewList
 from docutils.parsers.rst.directives.html import MetaBody
 
 from sphinx import addnodes
-from sphinx.versioning import make_diff, add_uids, merge_doctrees
+from sphinx.versioning import add_uids, merge_doctrees
 
 def setup_module():
     global app, original, original_uids
@@ -36,18 +36,6 @@ doctrees = {}
 def on_doctree_resolved(app, doctree, docname):
     doctrees[docname] = doctree
 
-def test_make_diff():
-    tests = [
-        (('aaa', 'aaa'), (True, False, False)),
-        (('aaa', 'aab'), (False, True, False)),
-        (('aaa', 'abb'), (False, True, False)),
-        (('aaa', 'aba'), (False, True, False)),
-        (('aaa', 'baa'), (False, True, False)),
-        (('aaa', 'bbb'), (False, False, True))
-    ]
-    for args, result in tests:
-        assert make_diff(*args) == result
-
 def is_paragraph(node):
     return node.__class__.__name__ == 'paragraph'