more merge fixes

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more merge fixes

Logic for getting a remote change should work going backwards and forwards

Mark all the changes in the merge that we don't get or merge so we
have the right list of files in the changeset

manifest hash: 88be742f510a2c58b276172ae538f9533f5e7491
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mercurial/hg.py

@@ -886,6 +886,7 b' class localrepository:'
             return
 
         p1, p2 = pl[0], node
+        pa = self.changelog.ancestor(p1, p2)
         m1n = self.changelog.read(p1)[0]
         m2n = self.changelog.read(p2)[0]
         man = self.manifest.ancestor(m1n, m2n)
@@ -907,6 +908,7 b' class localrepository:'
         merge = {}
         get = {}
         remove = []
+        mark = {}
 
         # construct a working dir manifest
         mw = m1.copy()
@@ -934,11 +936,15 b' class localrepository:'
                         mode = ((a^b) | (a^c)) ^ a
                         merge[f] = (m1.get(f, nullid), m2[f], mode)
                         s = 1
-                    # is this an unmodified file or are we clobbering?
-                    elif mw[f] == m1[f] or force:
+                    # are we clobbering?
+                    # is remote's version newer?
+                    # or are we going back in time?
+                    elif force or m2[f] != a or (p2 == pa and mw[f] == m1[f]):
                         self.ui.debug(" remote %s is newer, get\n" % f)
                         get[f] = m2[f]
                         s = 1
+                    else:
+                        mark[f] = 1
 
                 if not s and mfw[f] != mf2[f]:
                     if force:
@@ -950,7 +956,7 b' class localrepository:'
                         if mode != b:
                             self.ui.debug(" updating permissions for %s\n" % f)
                             set_exec(self.wjoin(f), mode)
-
+                            mark[f] = 1
                 del m2[f]
             elif f in ma:
                 if not force and n != ma[f]:
@@ -987,22 +993,28 b' class localrepository:'
                 get[f] = merge[f][1]
             merge = {}
 
-        if not merge:
+        if pa == p1 or pa == p2:
             # we don't need to do any magic, just jump to the new rev
             mode = 'n'
             p1, p2 = p2, nullid
         else:
             if not allow:
-                self.ui.status("the following files conflict:\n")
-                for f in merge:
-                    self.ui.status(" %s\n" % f)
-                self.ui.warn("aborting update due to conflicting files!\n")
-                self.ui.status("(use update -m to allow a merge)\n")
+                self.ui.status("this update spans a branch" +
+                               " affecting the following files:\n")
+                fl = merge.keys() + get.keys()
+                fl.sort()
+                for f in fl:
+                    cf = ""
+                    if f in merge: cf = " (resolve)"
+                    self.ui.status(" %s%s\n" % (f, cf))
+                self.ui.warn("aborting update spanning branches!\n")
+                self.ui.status("(use update -m to perform a branch merge)\n")
                 return 1
             # we have to remember what files we needed to get/change
             # because any file that's different from either one of its
             # parents must be in the changeset
             mode = 'm'
+            self.dirstate.update(mark.keys(), "m")
 
         self.dirstate.setparents(p1, p2)