PR#4413: Fix race handling in get_next_build

Merges #4413
https://pagure.io/koji/pull-request/4413

Fixes: #4414
https://pagure.io/koji/issue/4414
Fix race handling in get_next_build

kojihub/kojihub.py

@@ -4859,9 +4859,12 @@ def get_next_build(build_info):
         return new_build(build_info)
     build_info['release'] = get_next_release(build_info)
     for try_no in range(2, 10):
+        savepoint = Savepoint('get_next_build_pre_insert')
         try:
-            return new_build(build_info)
-        except IntegrityError:
+            # using strict so we don't try to recycle
+            return new_build(build_info, strict=True)
+        except (IntegrityError, koji.GenericError):
+            savepoint.rollback()
             build_info['release'] = get_next_release(build_info, try_no)
     # otherwise
     raise koji.GenericError("Can't find available release")

tests/test_hub/test_get_next_build.py

@@ -12,6 +12,7 @@ class TestGetNextBuild(unittest.TestCase):
         self.get_next_release = mock.patch('kojihub.kojihub.get_next_release').start()
         self.new_build = mock.patch('kojihub.kojihub.new_build').start()
         self._dml = mock.patch('kojihub.kojihub._dml').start()
+        self.Savepoint = mock.patch('kojihub.kojihub.Savepoint').start()
         self.binfo = {'name': 'name', 'version': 'version'}
 
     def tearDown(self):