From 553a2c585db50599d5028ea6bb6462281bb88d02 Mon Sep 17 00:00:00 2001
From: Jaroslav Mracek <jmracek@redhat.com>
Date: Mon, 11 Jul 2022 12:27:14 +0200
Subject: [PATCH] Set default value for variable to prevent crash
 (RhBug:2091636)

It ensure that read of file ended successfully.

https://bugzilla.redhat.com/show_bug.cgi?id=2091636
---
 dnf/conf/substitutions.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/dnf/conf/substitutions.py b/dnf/conf/substitutions.py
index 703e4a4f..1281bdf0 100644
--- a/dnf/conf/substitutions.py
+++ b/dnf/conf/substitutions.py
@@ -53,6 +53,7 @@ class Substitutions(dict):
                 continue
             for fsvar in fsvars:
                 filepath = os.path.join(dir_fsvars, fsvar)
+                val = None
                 if os.path.isfile(filepath):
                     try:
                         with open(filepath) as fp:
@@ -61,4 +62,5 @@ class Substitutions(dict):
                             val = val[:-1]
                     except (OSError, IOError):
                         continue
-                self[fsvar] = val
+                if val is not None:
+                    self[fsvar] = val
-- 
2.37.1