# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 1163871259 21600
# Node ID 9103dab960932c5b1337dc6dad361437ce9a84e9
# Parent  eb0b4a2d70a9c650d22bad9df0772878af0ac4e0
avoid unnecessary copy merges

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -139,6 +139,8 @@ def findcopies(repo, m1, m2, ma, limit):
         ''' check if an apparent pair actually matches '''
         c2 = ctx(f2, man[f2])
         ca = c.ancestor(c2)
+        if c == ca or c2 == ca:
+            return
         if ca and ca.path() == c.path() or ca.path() == c2.path():
             copy[c.path()] = f2
             copy[f2] = c.path()
diff --git a/tests/test-merge8.out b/tests/test-merge8.out
--- a/tests/test-merge8.out
+++ b/tests/test-merge8.out
@@ -6,5 +6,4 @@ adding manifests
 adding file changes
 added 2 changesets with 2 changes to 1 files
 (run 'hg update' to get a working copy)
-merging a and b
-0 files updated, 1 files merged, 0 files removed, 0 files unresolved
+1 files updated, 0 files merged, 1 files removed, 0 files unresolved
diff --git a/tests/test-rename-merge2.out b/tests/test-rename-merge2.out
--- a/tests/test-rename-merge2.out
+++ b/tests/test-rename-merge2.out
@@ -88,15 +88,14 @@ resolving manifests
  overwrite None partial False
  ancestor 924404dff337 local 94b33a1b7f2d+ remote 735846fee2d7
  rev: versions differ -> m
- a: remote copied -> m
-copying a to b
+ b: remote created -> g
+getting b
 merging rev
 my rev@94b33a1b7f2d+ other rev@735846fee2d7 ancestor rev@924404dff337
 1 files updated, 1 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
 --------------
 M b
-  a
 C a
 --------------
 
@@ -106,16 +105,14 @@ test L:nc a b R:       W:       - 6  not
 resolving manifests
  overwrite None partial False
  ancestor 924404dff337 local ac809aeed39a+ remote 97c705ade336
- b: local copied -> m
  rev: versions differ -> m
 merging rev
 my rev@ac809aeed39a+ other rev@97c705ade336 ancestor rev@924404dff337
-1 files updated, 1 files merged, 0 files removed, 0 files unresolved
+0 files updated, 1 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
 --------------
-M b
-  a
 C a
+C b
 --------------
 
 --------------
@@ -124,17 +121,17 @@ test L:       R:nm a b W:       - 7  get
 resolving manifests
  overwrite None partial False
  ancestor 924404dff337 local 94b33a1b7f2d+ remote e03727d2d66b
- a: remote moved -> m
+ a: other deleted -> r
  rev: versions differ -> m
-copying a to b
+ b: remote created -> g
 removing a
+getting b
 merging rev
 my rev@94b33a1b7f2d+ other rev@e03727d2d66b ancestor rev@924404dff337
-1 files updated, 1 files merged, 0 files removed, 0 files unresolved
+1 files updated, 1 files merged, 1 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
 --------------
 M b
-  a
 --------------
 
 --------------
@@ -143,15 +140,13 @@ test L:nm a b R:       W:       - 8  not
 resolving manifests
  overwrite None partial False
  ancestor 924404dff337 local ecf3cb2a4219+ remote 97c705ade336
- b: local moved -> m
  rev: versions differ -> m
 merging rev
 my rev@ecf3cb2a4219+ other rev@97c705ade336 ancestor rev@924404dff337
-1 files updated, 1 files merged, 0 files removed, 0 files unresolved
+0 files updated, 1 files merged, 0 files removed, 0 files unresolved
 (branch merge, don't forget to commit)
 --------------
-M b
-  a
+C b
 --------------
 
 --------------