Fix the directory and revlog collision problem

Fix the directory and revlog collision problem

This adds escaping for directory names so that directory foo.i doesn't
collide with the revision data for file foo.

--- a/mercurial/hg.py	Wed Jul 27 18:16:20 2005 -0800
+++ b/mercurial/hg.py	Wed Jul 27 18:50:32 2005 -0800
@@ -16,8 +16,22 @@
 class filelog(revlog):
     def __init__(self, opener, path):
         revlog.__init__(self, opener,
-                        os.path.join("data", path + ".i"),
-                        os.path.join("data", path + ".d"))
+                        os.path.join("data", self.encodedir(path + ".i")),
+                        os.path.join("data", self.encodedir(path + ".d")))
+
+    # This avoids a collision between a file named foo and a dir named
+    # foo.i or foo.d
+    def encodedir(self, path):
+        path.replace(".hg/", ".hg.hg/")
+        path.replace(".i/", ".i.hg/")
+        path.replace(".d/", ".i.hg/")
+        return path
+
+    def decodedir(self, path):
+        path.replace(".d.hg/", ".d/")
+        path.replace(".i.hg/", ".i/")
+        path.replace(".hg.hg/", ".hg/")
+        return path
 
     def read(self, node):
         t = self.revision(node)