diff -r 6359976b43be -r c93cdfa131a8 mercurial/context.py
--- a/mercurial/context.py	Mon Mar 20 17:58:44 2017 -0400
+++ b/mercurial/context.py	Fri Mar 24 22:13:23 2017 +0900
@@ -1864,8 +1864,8 @@
     commit function for every file in 'files', but calls order is
     undefined. If the file is available in the revision being
     committed (updated or added), filectxfn returns a memfilectx
-    object. If the file was removed, filectxfn raises an
-    IOError. Moved files are represented by marking the source file
+    object. If the file was removed, filectxfn return None for recent
+    Mercurial. Moved files are represented by marking the source file
     removed and the new file added with copy information (see
     memfilectx).