From 06ceda20de0cf1dedf76765d05c76993b4ab05f8 Mon Sep 17 00:00:00 2001
From: Philipp Kilian <kilian@ibh.de>
Date: Thu, 2 Nov 2023 16:49:39 +0100
Subject: [PATCH] models: fix value check for empty values

---
 b3lb/rest/models.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/b3lb/rest/models.py b/b3lb/rest/models.py
index 454fc4d..98794c3 100644
--- a/b3lb/rest/models.py
+++ b/b3lb/rest/models.py
@@ -1258,7 +1258,7 @@ class Parameter(models.Model):
 
     def clean_fields(self, exclude=None):
         if self.mode in [self.SET, self.OVERRIDE]:
-            if not match(self.PARAMETER_REGEXES[self.parameter], self.value):
+            if not (self.value and match(self.PARAMETER_REGEXES[self.parameter], self.value)):
                 raise ValidationError(f'Value must have the format "{self.PARAMETER_REGEXES[self.parameter]}"!', params={'value': self.value})
 
     class Meta(object):