hub: [groupListRemove] raise Error when no group for tag

Fixes: https://pagure.io/koji/issue/1090

hub/kojihub.py

@@ -1724,6 +1724,16 @@ def _grplist_add(taginfo, grpinfo, block, force, **opts):
 
 def grplist_remove(taginfo, grpinfo, force=False):
     """Remove group from the list for tag
+    Permission required: admin
+
+    :param taginfo: tag id or name which group is removed from
+    :type taginfo: int or str
+    :param grpinfo: group id or name which is removed
+    :type grpinfo: int or str
+    :param bool force: If False(default), GenericException will be raised when
+                       no group found in the list for tag. If True, revoking
+                       will be force to execute, no matter if the relationship
+                       exists.
 
     Really this shouldn't be used except in special cases
     Most of the time you really want to use the block or unblock functions
@@ -1733,13 +1743,22 @@ def grplist_remove(taginfo, grpinfo, force=False):
     _grplist_remove(taginfo, grpinfo, force)
 
 
-def _grplist_remove(taginfo, grpinfo, force):
+def _grplist_remove(taginfo, grpinfo, force=False):
     """grplist_remove without permission check"""
     tag = get_tag(taginfo, strict=True)
     group = lookup_group(grpinfo, strict=True)
     tag_id = tag['id']
     grp_id = group['id']
     clauses = ['group_id=%(grp_id)s', 'tag_id=%(tag_id)s']
+    if not force:
+        query = QueryProcessor(columns=['id'],
+                               tables=['group_config'],
+                               values=locals(),
+                               clauses=clauses + [eventCondition(None)])
+        old_grp_conf = query.executeOne()
+        if not old_grp_conf:
+            raise koji.GenericError("No group: %s found for tag: %s"
+                                    % (tag['name'], group['name']))
     update = UpdateProcessor('group_config', values=locals(), clauses=clauses)
     update.make_revoke()
     update.execute()

tests/test_hub/test_group_operations.py

@@ -18,6 +18,13 @@ class TestGrouplist(unittest.TestCase):
         self.queries.append(query)
         return query
 
+    def getEmptyQuery(self, *args, **kwargs):
+        query = QP(*args, **kwargs)
+        query.execute = mock.MagicMock()
+        query.execute.return_value = None
+        self.queries.append(query)
+        return query
+
     def getInsert(self, *args, **kwargs):
         insert = IP(*args, **kwargs)
         insert.execute = mock.MagicMock()
@@ -30,6 +37,11 @@ class TestGrouplist(unittest.TestCase):
         self.updates.append(update)
         return update
 
+    def reset_db_processors(self):
+        self.queries = []
+        self.updates = []
+        self.inserts = []
+
     def setUp(self):
         self.context = mock.patch('kojihub.context').start()
         self.get_tag = mock.patch('kojihub.get_tag').start()
@@ -171,13 +183,42 @@ class TestGrouplist(unittest.TestCase):
         self.lookup_group.assert_called_once_with(group, strict=True)
 
         # db
+        self.assertEqual(len(self.queries), 1)
         self.assertEqual(len(self.inserts), 0)
         self.assertEqual(len(self.updates), 1)
+        query = self.queries[0]
+        self.assertEqual(' '.join(str(query).split()),
+                         'SELECT id FROM group_config'
+                         ' WHERE (group_id=%(grp_id)s)'
+                         ' AND (tag_id=%(tag_id)s)'
+                         ' AND ((active = TRUE))')
         update = self.updates[0]
         self.assertEqual(update.table, 'group_config')
         self.assertEqual(update.data, {'revoke_event': 42, 'revoker_id': 24})
         self.assertEqual(update.rawdata, {'active': 'NULL'})
 
+        # no group for tag found
+        self.reset_db_processors()
+        with mock.patch('kojihub.QueryProcessor', side_effect=self.getEmptyQuery):
+            with self.assertRaises(koji.GenericError) as cm:
+                kojihub.grplist_remove(tag, group)
+
+        self.assertEqual(len(self.queries), 1)
+        self.assertEqual(len(self.inserts), 0)
+        self.assertEqual(len(self.updates), 0)
+        self.assertEqual(cm.exception.args[0],
+                         'No group: tag found for tag: group')
+
+        # force = True
+        self.reset_db_processors()
+        with mock.patch('kojihub.QueryProcessor',
+                        side_effect=self.getEmptyQuery):
+            kojihub.grplist_remove(tag, group, force=True)
+
+        self.assertEqual(len(self.queries), 0)
+        self.assertEqual(len(self.inserts), 0)
+        self.assertEqual(len(self.updates), 1)
+
     def test_grplist_unblock(self):
         # identical with test_grplist_add except blocked=True
         tag = 'tag'