…s-grekas)

This PR was merged into the 4.2 branch.

Discussion
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[Routing] fix matching trailing vars with defaults

| Q             | A
| ------------- | ---
| Branch?       | 4.2
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #31158
| License       | MIT
| Doc PR        | -

Commits
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177dfbc [Routing] fix matching trailing vars with defaults

…trailing vars (nicolas-grekas)

This PR was merged into the 4.2 branch.

Discussion
----------

[Routing] fix trailing slash matching with empty-matching trailing vars

| Q             | A
| ------------- | ---
| Branch?       | 4.2
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Reported by @bmack in #31107 (comment)

This highlights a small inconsistency that exists for a long time (checked on 2.7 at least):
`new Route('/en-en/{b}', ['b' => 'bbb'], ['b' => '.*'])` matches `/en-en/`
`new Route('/en-en/{b}', ['b' => 'bbb'], ['b' => '.+'])` doesn't match it
(while both match `/en-en` and `/en-en/foo`)

This PR ensures the former behavior is preserved, while #31167 redirects the later to `/en-en`.

Commits
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d6da21a [Routing] fix trailing slash matching with empty-matching trailing vars