diff -r d90c534099b1 -r 70e86db6a913 mercurial/dagop.py
--- a/mercurial/dagop.py	Sun Oct 22 17:23:34 2017 +0900
+++ b/mercurial/dagop.py	Thu Sep 22 17:48:46 2016 +0900
@@ -76,7 +76,7 @@
                     heapq.heappush(pendingheap, (heapsign * prev, pdepth))
 
 def filectxancestors(fctx, followfirst=False):
-    """Like filectx.ancestors()"""
+    """Like filectx.ancestors(), but includes the given fctx itself"""
     visit = {}
     c = fctx
     if followfirst:
@@ -84,6 +84,7 @@
     else:
         cut = None
 
+    yield c
     while True:
         for parent in c.parents()[:cut]:
             visit[(parent.linkrev(), parent.filenode())] = parent