--- a/mercurial/ui.py	Fri Jan 13 23:21:10 2017 -0800
+++ b/mercurial/ui.py	Sat Jan 14 20:31:35 2017 +0900
@@ -972,7 +972,10 @@
             # disable getpass() only if explicitly specified. it's still valid
             # to interact with tty even if fin is not a tty.
             if self.configbool('ui', 'nontty'):
-                return self.fin.readline().rstrip('\n')
+                l = self.fin.readline()
+                if not l:
+                    raise EOFError
+                return l.rstrip('\n')
             else:
                 return getpass.getpass('')
         except EOFError:

--- a/tests/test-commandserver.t	Fri Jan 13 23:21:10 2017 -0800
+++ b/tests/test-commandserver.t	Sat Jan 14 20:31:35 2017 +0900
@@ -607,6 +607,12 @@
   ...     runcommand(server, ['debuggetpass', '--config',
   ...                         'ui.interactive=True'],
   ...                input=stringio('1234\n'))
+  ...     runcommand(server, ['debuggetpass', '--config',
+  ...                         'ui.interactive=True'],
+  ...                input=stringio('\n'))
+  ...     runcommand(server, ['debuggetpass', '--config',
+  ...                         'ui.interactive=True'],
+  ...                input=stringio(''))
   ...     runcommand(server, ['debugprompt', '--config',
   ...                         'ui.interactive=True'],
   ...                input=stringio('5678\n'))
@@ -614,6 +620,11 @@
   ...     runcommand(server, ['debugwritestdout'])
   *** runcommand debuggetpass --config ui.interactive=True
   password: 1234
+  *** runcommand debuggetpass --config ui.interactive=True
+  password: 
+  *** runcommand debuggetpass --config ui.interactive=True
+  password: abort: response expected
+   [255]
   *** runcommand debugprompt --config ui.interactive=True
   prompt: 5678
   *** runcommand debugreadstdin