[JENKINS-64529] unhandled exception after updating gitlab branch source plugin to 1.5.3

after updating GitLab branch source plugin to the latest version, I started receiving JENKINS-64529">gitlab_branch_source_exception.txtin the server log every time a webhook is activated from the gitlab server.

this didn't happen with gitlab branch source plugin 1.5.1.

---
Originally reported by amidar, imported from: unhandled exception after updating gitlab branch source plugin to 1.5.3

• assignee: surenpi
  
• status: Open
  
• priority: Major
  
• component(s): gitlab-branch-source-plugin
  
• resolution: Unresolved
  
• votes: 2
  
• watchers: 6
  
• imported: 20251216-182730
  

Raw content of original issue

after updating GitLab branch source plugin to the latest version, I started receiving gitlab_branch_source_exception.txtin the server log every time a webhook is activated from the gitlab server.


this didn't happen with gitlab branch source plugin 1.5.1.

environment

```
jenkins 2.263.1

gitlab ee 13.3.5

gitlab branch source 1.5.3
```

1 attachment

- [gitlab_branch_source_exception.txt](https://issues.jenkins.io/secure/attachment/53734/gitlab_branch_source_exception.txt)

Start by reviewing the attached gitlab_branch_source_exception.txt and the webhook handling path in the gitlab-branch-source-plugin. Compare behavior between plugin versions 1.5.1 and 1.5.3; done means identifying and fixing the cause of the exception when a GitLab webhook is activated, with no corresponding server-log error.

Written by the indexing model from the issue text.