mercurial/manifest.py

--- a/mercurial/manifest.py	Sat Feb 25 03:42:43 2017 +0530
+++ b/mercurial/manifest.py	Sun Feb 26 10:16:47 2017 -0800
@@ -1386,7 +1386,7 @@
         return self._revlog().parents(self._node)
 
     def read(self):
-        if not self._data:
+        if self._data is None:
             if self._node == revlog.nullid:
                 self._data = manifestdict()
             else:
@@ -1484,7 +1484,7 @@
         return self._repo.manifestlog._revlog.dirlog(self._dir)
 
     def read(self):
-        if not self._data:
+        if self._data is None:
             rl = self._revlog()
             if self._node == revlog.nullid:
                 self._data = treemanifest()