Steps to reproduce

Using the mysql2 gem, open a console with DATABASE_URL using wait_timeout configuration, e.g.:

DATABASE_URL="mysql2://localhost:3306/test-db?wait_timeout=60&checkout_timeout=42" bundle exec rails console

pry(main)> ActiveRecord::Base.connection.execute("SHOW VARIABLES LIKE \"wait_timeout\"").to_a
=> [["wait_timeout", "2147483"]]

I believe the culprit is the Integer/Fixnum check here, which was introduced as some sort of backwards compatibility, because wait_timeout was also used by the connection pool configuration.

There is no way to get the parameter typed as Integer when using a DATABASE_URL, which seems like undesirable behaviour from my point of view.

Expected behavior

The configured wait_timeout should be 60 all connections.

Actual behavior

The configured wait_timeout is the default of 2147483 on all connections.

System configuration

Rails version:
Tested with ActiveRecord 4.2.7.1, possibly more versions affected.

Ruby version:
Tested with ruby 2.3.1