diff -r b5040a9cb84c -r 48157f198a04 mercurial/context.py
--- a/mercurial/context.py	Fri Aug 10 09:20:44 2018 +0900
+++ b/mercurial/context.py	Tue Aug 14 13:36:11 2018 -0700
@@ -593,12 +593,6 @@
                             short(n) for n in sorted(cahs) if n != anc))
         return changectx(self._repo, anc)
 
-    def descendant(self, other):
-        msg = (b'ctx.descendant(other) is deprecated, '
-               b'use ctx.isancestorof(other)')
-        self._repo.ui.deprecwarn(msg, b'4.7')
-        return self.isancestorof(other)
-
     def isancestorof(self, other):
         """True if this changeset is an ancestor of other"""
         return self._repo.changelog.isancestorrev(self._rev, other._rev)