From 46f7785e28c17f33252a95a57dd3827811291394 Mon Sep 17 00:00:00 2001
From: Yury Selivanov <yselivanov@sprymix.com>
Date: Thu, 4 Feb 2016 14:00:26 -0500
Subject: [PATCH] Issue #25660: Fix a unittest and rlcompleter when readline
 isn't available

---
 Lib/rlcompleter.py           | 12 ++++++++----
 Lib/test/test_rlcompleter.py |  2 ++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/Lib/rlcompleter.py b/Lib/rlcompleter.py
index 26f59208bb4..401a6261798 100644
--- a/Lib/rlcompleter.py
+++ b/Lib/rlcompleter.py
@@ -75,9 +75,12 @@ class Completer:
 
         if not text.strip():
             if state == 0:
-                readline.insert_text('\t')
-                readline.redisplay()
-                return ''
+                if _readline_available:
+                    readline.insert_text('\t')
+                    readline.redisplay()
+                    return ''
+                else:
+                    return '\t'
             else:
                 return None
 
@@ -170,10 +173,11 @@ def get_class_members(klass):
 try:
     import readline
 except ImportError:
-    pass
+    _readline_available = False
 else:
     readline.set_completer(Completer().complete)
     # Release references early at shutdown (the readline module's
     # contents are quasi-immortal, and the completer function holds a
     # reference to globals).
     atexit.register(lambda: readline.set_completer(None))
+    _readline_available = True
diff --git a/Lib/test/test_rlcompleter.py b/Lib/test/test_rlcompleter.py
index 2d5d9c1f70b..853e77330aa 100644
--- a/Lib/test/test_rlcompleter.py
+++ b/Lib/test/test_rlcompleter.py
@@ -1,4 +1,5 @@
 import unittest
+import unittest.mock
 import builtins
 import rlcompleter
 
@@ -77,6 +78,7 @@ class TestRlcompleter(unittest.TestCase):
         self.assertEqual(completer.complete('f.b', 0), 'f.bar')
         self.assertEqual(f.calls, 1)
 
+    @unittest.mock.patch('rlcompleter._readline_available', False)
     def test_complete(self):
         completer = rlcompleter.Completer()
         self.assertEqual(completer.complete('', 0), '\t')