diff -r 7279e0132347 -r 1ac8ce137377 mercurial/manifest.py
--- a/mercurial/manifest.py	Sun Dec 27 20:21:37 2015 +0900
+++ b/mercurial/manifest.py	Fri Feb 12 23:09:09 2016 -0800
@@ -985,6 +985,15 @@
             return self.readdelta(node)
         return self.read(node)
 
+    def readshallowfast(self, node):
+        '''like readfast(), but calls readshallowdelta() instead of readdelta()
+        '''
+        r = self.rev(node)
+        deltaparent = self.deltaparent(r)
+        if deltaparent != revlog.nullrev and deltaparent in self.parentrevs(r):
+            return self.readshallowdelta(node)
+        return self.readshallow(node)
+
     def read(self, node):
         if node == revlog.nullid:
             return self._newmanifest() # don't upset local cache
@@ -1006,6 +1015,13 @@
         self._mancache[node] = (m, arraytext)
         return m
 
+    def readshallow(self, node):
+        '''Reads the manifest in this directory. When using flat manifests,
+        this manifest will generally have files in subdirectories in it. Does
+        not cache the manifest as the callers generally do not read the same
+        version twice.'''
+        return manifestdict(self.revision(node))
+
     def find(self, node, f):
         '''look up entry for a single file efficiently.
         return (node, flags) pair if found, (None, None) if not.'''