# HG changeset patch
# User Bryan O'Sullivan <bryano@fb.com>
# Date 1360445076 0
# Node ID 0b6e6eacc939c303136cb38af108e307d640c26e
# Parent  18c2184c27dcb9a310152d67e5d4aa7cea92c7ba
merge: don't call copies.mergecopies unless we need to

This reduces the amount of time we spend calculating when doing a clean
non-merge update. In a large repo, the time dropped from 10.1 seconds
to 3.4.

diff -r 18c2184c27dc -r 0b6e6eacc939 mercurial/merge.py
--- a/mercurial/merge.py	Sat Feb 09 21:24:24 2013 +0000
+++ b/mercurial/merge.py	Sat Feb 09 21:24:36 2013 +0000
@@ -200,6 +200,8 @@
         pa = wctx
     elif pa == p2: # backwards
         pa = wctx.p1()
+    elif not branchmerge and not wctx.dirty(missing=True):
+        pass
     elif pa and repo.ui.configbool("merge", "followcopies", True):
         ret = copies.mergecopies(repo, wctx, p2, pa)
         copy, movewithdir, diverge, renamedelete = ret
diff -r 18c2184c27dc -r 0b6e6eacc939 tests/test-subrepo.t
--- a/tests/test-subrepo.t	Sat Feb 09 21:24:24 2013 +0000
+++ b/tests/test-subrepo.t	Sat Feb 09 21:24:36 2013 +0000
@@ -210,7 +210,6 @@
   subrepo merge f0d2028bf86d+ 1831e14459c4 1f14a2e2d3ec
     subrepo t: other changed, get t:6747d179aa9a688023c4b0cad32e4c92bb7f34ad:hg
   getting subrepo t
-    searching for copies back to rev 1
   resolving manifests
    branchmerge: False, force: False, partial: False
    ancestor: 60ca1237c194, local: 60ca1237c194+, remote: 6747d179aa9a