From b6484282f85bf7f11451b2441599c241d302ad9d Mon Sep 17 00:00:00 2001
From: Raul Tambre <raul@tambre.ee>
Date: Sat, 4 May 2019 15:48:17 -0400
Subject: [PATCH] Fix incorrect use of 'is' operator for comparison in
 python/lib/gdb/command/prompt.py

The 'is' operator is not meant to be used for comparisons. It currently working
is an implementation detail of CPython.  CPython 3.8 has added a SyntaxWarning
for this.

diff --git a/gdb/python/lib/gdb/command/prompt.py b/gdb/python/lib/gdb/command/prompt.py
index 3d662a7..04b9e49 100644
--- a/gdb/python/lib/gdb/command/prompt.py
+++ b/gdb/python/lib/gdb/command/prompt.py
@@ -45,7 +45,7 @@ The currently defined substitutions are:
         self.hook_set = False
 
     def get_show_string (self, pvalue):
-        if self.value is not '':
+        if self.value:
            return "The extended prompt is: " + self.value
         else:
            return "The extended prompt is not set."
@@ -57,7 +57,7 @@ The currently defined substitutions are:
         return ""
 
     def before_prompt_hook(self, current):
-        if self.value is not '':
+        if self.value:
             return gdb.prompt.substitute_prompt(self.value)
         else:
             return None