--- a/mercurial/revlog.py	Wed Aug 07 17:14:48 2019 +0200
+++ b/mercurial/revlog.py	Wed Aug 07 21:54:29 2019 +0200
@@ -1720,6 +1720,13 @@
 
         return text
 
+    def rawdata(self, nodeorrev, _df=None, raw=False):
+        """return an uncompressed raw data of a given node or revision number.
+
+        _df - an existing file handle to read from. (internal-only)
+        """
+        return self._revisiondata(nodeorrev, _df, raw=True)
+
     def hash(self, text, p1, p2):
         """Compute a node hash.