Closes #4835: Support passing multiple initial values for multiple choice fields

netbox/utilities/utils.py

@@ -150,6 +150,24 @@ def dict_to_filter_params(d, prefix=''):
     return params
 
 
+def normalize_querydict(querydict):
+    """
+    Convert a QueryDict to a normal, mutable dictionary, preserving list values. For example,
+
+        QueryDict('foo=1&bar=2&bar=3&baz=')
+
+    becomes:
+
+        {'foo': '1', 'bar': ['2', '3'], 'baz': ''}
+
+    This function is necessary because QueryDict does not provide any built-in mechanism which preserves multiple
+    values.
+    """
+    return {
+        k: v if len(v) > 1 else v[0] for k, v in querydict.lists()
+    }
+
+
 def deepmerge(original, new):
     """
     Deep merge two dictionaries (new into original) and return a new dict