### Motivation / Background

[xXxrAinSonic]

Motivation / Background

When routing a request, #find_routes will iterate through potential routes for the request and yield them to the passed block. #serve and #recognize both used #find_routes, but ended up handling things slightly differently. Both methods would modify the script_name and path_info of the request if the current route is not anchored. However, only #serve used #chomp and would restore the request's original script_name and path_info after each iteration. This inconsistency can cause issues as #recognize can end up not matching them even though #serve would.

Detail

This commit fixes the issue by unifying more of the implementations of #serve and #recognize. Now, #find_routes implements the mutation/restoration of request params for both #serve and #recognize so that their behavior is consistent and request mutation isn't leaked between iterations.

One test had to be changed because it depended on the request mutation leaking outside of #recognize, so it was updated to make assertions during #recognize instead.

Additional information

Fixes #31152

Checklist

Before submitting the PR make sure the following are checked:

• This Pull Request is related to one change. Unrelated changes 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.

Originally posted by @skipkayhil in rails/rails#54550

[xXxrAinSonic]

👍