Browse project searches are slow when JIRA has lots of projects

Summary

Due to a change made in JIRA 6.1.6, if there are a lot of projects, then a lot of SQL will be triggered by an issue search. As a result, any functionality which includes a browse project search will run very slowly. This includes some dashboard gadgets, and issue searches. This only happens when there is a permission scheme which allows "Browse Projects" permission for "Current Assignee".

Steps to Reproduce

1. Create a JIRA instance with a lot of projects, for example, more than 1000.
2. Add some issue search dashboard gadgets
3. Load the dashboard

Expected Results

1. The dashboard gadgets should load quickly, and not produce much database load for a single page load.

Actual Results

1. The dashboard gadgets take a long time to load
2. The database is hit with a large number of queries

Workaround

1. Remove "Current Assignee" from "Browse Projects" in all permissions schemes
2. Remain on 6.1.5 or below until a fix is created