fix errors in channel policy

Fixes: https://pagure.io/koji/issue/4065

koji/policy.py

@@ -135,8 +135,12 @@ class MatchTest(BaseSimpleTest):
             field = self.field
         if field not in data:
             return False
+        value = data[field]
+        if value is None:
+            # None does not match any pattern
+            return False
         for pattern in args:
-            if fnmatch.fnmatch(data[field], pattern):
+            if fnmatch.fnmatch(value, pattern):
                 return True
         return False
 

kojihub/kojihub.py

@@ -10150,7 +10150,8 @@ def policy_data_from_task_args(method, arglist):
                 target = tinfo['name']
         policy_data['target'] = target
 
-    t_opts = params.get('opts', {})
+    # we may have param['opts'] that is explicitly None
+    t_opts = params.get('opts') or {}
     policy_data['scratch'] = t_opts.get('scratch', False)
 
     return policy_data