From 0cf8ac5aa1dfcb8792bac9c96ba28c675790db25 2020-05-29 14:59:53
From: Matthias Bussonnier <bussonniermatthias@gmail.com>
Date: 2020-05-29 14:59:53
Subject: [PATCH] Merge pull request #12346 from meeseeksmachine/auto-backport-of-pr-12305-on-7.x

Backport PR #12305 on branch 7.x (Fix ipython#11508: check if line_buffer is None)
---

diff --git a/IPython/core/completer.py b/IPython/core/completer.py
index 32144e1..bc114f0 100644
--- a/IPython/core/completer.py
+++ b/IPython/core/completer.py
@@ -1982,8 +1982,8 @@ class IPCompleter(Completer):
         # if text is either None or an empty string, rely on the line buffer
         if (not line_buffer) and full_text:
             line_buffer = full_text.split('\n')[cursor_line]
-        if not text:
-            text = self.splitter.split_line(line_buffer, cursor_pos)
+        if not text: # issue #11508: check line_buffer before calling split_line
+            text = self.splitter.split_line(line_buffer, cursor_pos)  if line_buffer else ''
 
         if self.backslash_combining_completions:
             # allow deactivation of these on windows.