bpat1434/redmine_category_tree — pull request #6 by KappaNossi (2013-05-27 15:13:36+00:00)
Title: Fix for error 500 on Issue show with specific history entry

The Issue show page threw an error 500 (could not find Issue Category with ID nil) when accessing an Issue which has a history entry involving the Issue Category field. It occurs when the history states the Category change from or to an empty value.

A simple nil value check was introduced in the overridden IssueHelper method to prevent this from happening.