Setting hibernate.c3p0.min_size causes Confluence to use up to 7 times the specified connections, regardless of max_size on MySQL

Steps to reproduce

1. Setup a Confluence instance to point to a MySQL Database
2. Set the hibernate.c3p0.min_size property in confluence.cfg.xml to a non-zero value.
3. Monitor the number of connections created to the MySQL database over the next couple minutes with:

   select user, count(*) from information_schema.processlist group by user;

Expected Results

The database connections should stay between the bounds of min_size and max_size.

Actual Results

The database connections surpass the bound set in max_size, and end up being up to 7 times the number set in min_size.

Workaround

Setting the min_size value to 0 will lead to the max_size being obeyed.

Alternatively, if strict control of the number of connections is required, divide your intended connection pool size by 7 and set your min_size to this value.