Fix crash if there is id has already been reset to None

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/src/fireinfo/system.py b/src/fireinfo/system.py
index edf7359a17e6ec6d7e2d5fc3da2a3556ff804ca2..c2ba12e818f04737633c8c79b42cd09c8f2ffac4 100644 (file)
--- a/src/fireinfo/system.py
+++ b/src/fireinfo/system.py
@@ -256,7 +256,7 @@ class System(object):
                                                break
 
                        # Check if the string only contains 0xff
-                       if all((e == "\xff" for e in id)):
+                       if id and all((e == "\xff" for e in id)):
                                id = None
 
                        if id: