additional note about routes in functional tests for engines [ci skip]
Changed the NullRelation so that when count is called with #group it will properly return an empty hash instead of zero. Fixes issue #14721

Conflicts:
	activerecord/CHANGELOG.md
Merge pull request #11836 from mcfiredrill/engines-testing-doc

additional note about routes in functional tests for engines [ci skip]
`sanitize_sql_like` escapes `escape_character` not only backslash.

* This is a follow up to: fe4b0eee05f59831e1468ed50f55fbad0ce11e1d
* The originating PR is #14222
* It should fix the build
Merge pull request #14773 from eric-chahin/null_relation_fix

Changed the NullRelation so that when count is called with #group it wil...