Previously Rails auto-generated alt text for an image from the file name if it was not provided with an  image_tag.
This generation could be distracting and fatiguing for screen reader users if not considered properly.

After this change, if authors leave images without alt text, Rails will not pre fill it anymore, leaving screen readers to prompt authors to fix the issue.

Previously Rails would end up setting database connection timezone twice, once if passed via configuration in configure_connection and secondly while setting default timezone.

This change removes setting timezone on database twice if timezone is already passed via configuration variables.

This PR adds TransactionTimeout error to the MySQL adapter, which handles the error:
Lock wait timeout exceeded; try restarting transaction (MySQL error 1205) 

Before this change, urls for files with non-english names would create issues in Active Storage.

This change fixes encoding Content-Disposition for filenames to RFC 2231, to fix this issue.

For signed/encrypted cookies with :expires like

cookies.signed[:user_name] = { value: "bob", expires: 2.hours }

Rails now embeds the expiry within the written cookie payload. This way Rails isn't reliant on clients to honor the expiry, but can verify it independently server-side.

Previously rails dev:cache failed to restart the Rails server when it was started with a custom pid file path.
With this change, restart no longer fails for a custom pid file and successfully restarts Rails server on dev:cache changes.

This change does a quick fix for an error with display_image in System tests, which is used for screenshots, that used to raise an error when trying to modify a frozen string.

Previously calling an eager_load on :inverse_of association failed. 
This was a regression from Rails 5.1 release. 

This change, fixes the regression.