Handle undeletion of files when checking out old revisions

Spotted by Marc Singer

mercurial/hg.py

@@ -1394,9 +1394,11 b' class localrepository:'
                 self.ui.debug("remote created %s\n" % f)
                 get[f] = n
             else:
-                self.ui.debug("local deleted %s\n" % f)
-                if force:
+                if force or p2 == pa: # going backwards?
+                    self.ui.debug("local deleted %s, recreating\n" % f)
                     get[f] = n
+                else:
+                    self.ui.debug("local deleted %s\n" % f)
 
         del mw, m1, m2, ma