changeset 24415:1cfded2fa1a9

merge with stable

--- a/mercurial/context.py	Fri Mar 20 16:39:07 2015 -0500
+++ b/mercurial/context.py	Fri Mar 20 17:30:38 2015 -0500
@@ -775,13 +775,19 @@
         # hack to reuse ancestor computation when searching for renames
         memberanc = getattr(self, '_ancestrycontext', None)
         iteranc = None
+        if srcrev is None:
+            # wctx case, used by workingfilectx during mergecopy
+            revs = [p.rev() for p in self._repo[None].parents()]
+            inclusive = True # we skipped the real (revless) source
+        else:
+            revs = [srcrev]
         if memberanc is None:
-            memberanc = iteranc = cl.ancestors([srcrev], lkr,
+            memberanc = iteranc = cl.ancestors(revs, lkr,
                                                inclusive=inclusive)
         # check if this linkrev is an ancestor of srcrev
         if lkr not in memberanc:
             if iteranc is None:
-                iteranc = cl.ancestors([srcrev], lkr, inclusive=inclusive)
+                iteranc = cl.ancestors(revs, lkr, inclusive=inclusive)
             for a in iteranc:
                 ac = cl.read(a) # get changeset data (we avoid object creation)
                 if path in ac[3]: # checking the 'files' field.
@@ -914,6 +920,8 @@
         introrev = self.introrev()
         if self.rev() != introrev:
             base = self.filectx(self.filenode(), changeid=introrev)
+            ac = self._repo.changelog.ancestors([introrev], inclusive=True)
+            base._ancestrycontext = ac
 
         # This algorithm would prefer to be recursive, but Python is a
         # bit recursion-hostile. Instead we do an iterative

--- a/mercurial/copies.py	Fri Mar 20 16:39:07 2015 -0500
+++ b/mercurial/copies.py	Fri Mar 20 17:30:38 2015 -0500
@@ -266,14 +266,41 @@
     m2 = c2.manifest()
     ma = ca.manifest()
 
-    def makectx(f, n):
-        if len(n) != 20: # in a working context?
-            if c1.rev() is None:
-                return c1.filectx(f)
-            return c2.filectx(f)
-        return repo.filectx(f, fileid=n)
+
+    def setupctx(ctx):
+        """return a 'makectx' function suitable for checkcopies usage from ctx
+
+        We have to re-setup the function building 'filectx' for each
+        'checkcopies' to ensure the linkrev adjustement is properly setup for
+        each. Linkrev adjustment is important to avoid bug in rename
+        detection. Moreover, having a proper '_ancestrycontext' setup ensures
+        the performance impact of this adjustment is kept limited. Without it,
+        each file could do a full dag traversal making the time complexity of
+        the operation explode (see issue4537).
 
-    ctx = util.lrucachefunc(makectx)
+        This function exists here mostly to limit the impact on stable. Feel
+        free to refactor on default.
+        """
+        rev = ctx.rev()
+        ac = getattr(ctx, '_ancestrycontext', None)
+        if ac is None:
+            revs = [rev]
+            if rev is None:
+                revs = [p.rev() for p in ctx.parents()]
+            ac = ctx._repo.changelog.ancestors(revs, inclusive=True)
+            ctx._ancestrycontext = ac
+        def makectx(f, n):
+            if len(n) != 20:  # in a working context?
+                if c1.rev() is None:
+                    return c1.filectx(f)
+                return c2.filectx(f)
+            fctx = repo.filectx(f, fileid=n)
+            # setup only needed for filectx not create from a changectx
+            fctx._ancestrycontext = ac
+            fctx._descendantrev = rev
+            return fctx
+        return util.lrucachefunc(makectx)
+
     copy = {}
     movewithdir = {}
     fullcopy = {}
@@ -286,9 +313,11 @@
     u1, u2 = _computenonoverlap(repo, m1, m2, addedinm1, addedinm2)
 
     for f in u1:
+        ctx = setupctx(c1)
         checkcopies(ctx, f, m1, m2, ca, limit, diverge, copy, fullcopy)
 
     for f in u2:
+        ctx = setupctx(c2)
         checkcopies(ctx, f, m2, m1, ca, limit, diverge, copy, fullcopy)
 
     renamedelete = {}
@@ -311,7 +340,9 @@
                       % "\n   ".join(bothnew))
     bothdiverge, _copy, _fullcopy = {}, {}, {}
     for f in bothnew:
+        ctx = setupctx(c1)
         checkcopies(ctx, f, m1, m2, ca, limit, bothdiverge, _copy, _fullcopy)
+        ctx = setupctx(c2)
         checkcopies(ctx, f, m2, m1, ca, limit, bothdiverge, _copy, _fullcopy)
     for of, fl in bothdiverge.items():
         if len(fl) == 2 and fl[0] == fl[1]: