Fix empty string saving for ranges

[szymonlipka]

Motivation / Background

Fixes #48486

Saving ranges with an empty range

Detail

Simply return if the string is empty, the same as it's being done for an "empty" string.

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs.
• Commit message has a detailed description of what changed and why. If this PR fixes a related issue include it in the commit message. Ex: [Fix #issue-number]
• Tests are added or updated if you fix a bug or add a feature.
• CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature. Minor bug fixes and documentation changes should not be included.

[clairity]

ha, i'd tried something similar, and while it worked on the rails console, it didn't work when put through a form submit request cycle in my rails app, so i thought it wasn't working. turns out i forgot to restart the rails server to get the server to pick up the change.

[ghiculescu]

Could you add a test? It would probably go in https://github.com/rails/rails/blob/main/activerecord/test/cases/adapters/postgresql/range_test.rb

[szymonlipka]

Could you add a test? It would probably go in https://github.com/rails/rails/blob/main/activerecord/test/cases/adapters/postgresql/range_test.rb

Right, done

[szymonlipka]

@ghiculescu buildkite has failed, but I believe it might not be be related. Can I somehow retry the job?

[ghiculescu]

Easiest way to retry would be to rebase against main.

[szymonlipka]

@ghiculescu the CI has passed.