From 83d273e24b28b9c06f0fa4f5bf90581db7c29be8 2017-01-10 14:10:27
From: Thomas Kluyver <thomas@kluyver.me.uk>
Date: 2017-01-10 14:10:27
Subject: [PATCH] Fix newline check when prompt consists of empty token

---

diff --git a/IPython/terminal/prompts.py b/IPython/terminal/prompts.py
index 7b916cd..2208852 100644
--- a/IPython/terminal/prompts.py
+++ b/IPython/terminal/prompts.py
@@ -68,10 +68,12 @@ class RichPromptDisplayHook(DisplayHook):
 
         if self.do_full_cache:
             tokens = self.shell.prompts.out_prompt_tokens()
-            if tokens and not tokens[-1][1].endswith('\n'):
+            prompt_txt = ''.join(s for t, s in tokens)
+            if prompt_txt and not prompt_txt.endswith('\n'):
                 # Ask for a newline before multiline output
                 self.prompt_end_newline = False
+
             if self.shell.pt_cli:
                 self.shell.pt_cli.print_tokens(tokens)
             else:
-                sys.stdout.write(''.join(s for t, s in tokens))
+                sys.stdout.write(prompt_txt)