flash doesn't pass objects #15522 [ci skip]
do not hold on to a stale connection object. fixes #15998
Tiny follow-up to #15987 and 088b4c3e [ci skip]
Revert "Merge pull request #15394 from morgoth/fix-automatic-maintaining-test-schema-for-sql-format"

This reverts commit 46139d33c06715e74ad450428ece3ee84da98579, reversing
changes made to 8f247871bb18b2e3036a05df5f62cbfe3b402586.

Conflicts:
	activerecord/CHANGELOG.md
Don't error when `dup`ing a record with no PK
Merge pull request #16007 from nishantmodak/flash_msg_as_string

flash doesn't pass objects #15522 [ci skip]
Merge pull request #16016 from sgrif/sg-dup

Don't error when `dup`ing a record with no PK
Fix typo
[ci skip] Changes some wording to better foreshadow what is coming up later.
This should prevent some anxiety readers may experience when the doc goes into something different than what it just explained. Also clarifies a statement about priority in engines and application environments

[ci skip] fixes double `the`

[ci skip] more clarifications

[ci skip] changes from tics to quotes