diff -r cb0afaf112e8 -r 30742c216abb mercurial/ui.py
--- a/mercurial/ui.py	Tue Mar 06 02:05:25 2018 -0600
+++ b/mercurial/ui.py	Tue Mar 06 02:14:11 2018 -0600
@@ -1278,7 +1278,13 @@
         # prompt ' ' must exist; otherwise readline may delete entire line
         # - http://bugs.python.org/issue12833
         with self.timeblockedsection('stdio'):
-            line = util.bytesinput(self.fin, self.fout, r' ')
+            sin, sout = sys.stdin, sys.stdout
+            try:
+                sys.stdin = encoding.strio(self.fin)
+                sys.stdout = encoding.strio(self.fout)
+                line = encoding.strtolocal(pycompat.rawinput(r' '))
+            finally:
+                sys.stdin, sys.stdout = sin, sout
 
         # When stdin is in binary mode on Windows, it can cause
         # raw_input() to emit an extra trailing carriage return