[Routing] fix trailing slash redirection with non-greedy trailing vars

[nicolas-grekas]

Q	A
Branch?	4.2
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#30863, #31066
License	MIT
Doc PR	-

Fixes redirecting /123/ to /123 when the route is defined as /{foo<\d+>}

[arjenm]

We have a set of special wild card routes for 'short urls' that eventually are redirected to a 'full url'. I.e. we can open https://example.org/$something or https://example.org/$something/ and the controller decides where to redirect depending on the value of '$something'.

But its utterly useless to first redirect to the variant with or without / and then redirecting to the final url. So we had both scenario's defined as route, one with '/{label}' and one with '/{label}/' which both were setup with the same _controller.

Up untill this fix that worked just fine. Now when requesting the one with 'something/', the browser is first redirect to the variant without / and then to whatever the controller decides.
I.e. the second route that's a perfect match is ignored due to the other route (imperfect match), doing an early return causing a redirect.

Is there any (clean) way now to define one or more routes to support this scenario, where we just don't care about that trailing slash. But where we do care that a user gets an unnecessary redirect.

[bmack]

Hey all,

FYI: we're at TYPO3 have hit a similar issue as @arjenm in our nightly builds, I'm currently digging into this change and find out how we at TYPO3 used Symfony Routing the wrong way or if it is a BC issue.

Will keep you updated.
Benni.

[nicolas-grekas]

Is there any (clean) way now to define one or more routes to support this scenario, where we just don't care about that trailing slash. But where we do care that a user gets an unnecessary redirect.

Would changing the order of those two routes work?

[nicolas-grekas]

The other best way is to create a single route that matches with and without the trailing slash in the tail requirement of your route.

[arjenm]

Is there any (clean) way now to define one or more routes to support this scenario, where we just don't care about that trailing slash. But where we do care that a user gets an unnecessary redirect.

Would changing the order of those two routes work?

I'm fairly certain that would cause a redirect for the non-slash version to the slash-version. Which I discovered in this bug: #30721

The other best way is to create a single route that matches with and without the trailing slash in the tail requirement of your route.

Ah, it seems to work with this as the very last route:

new Route(
        '/{label}{slash}',
        ['_controller' => [...], 'slash' => ''],
        ['label' => '[^/]+', 'slash' => '/?']
    )

[bmack]

Hey,

I added a test to UrlMatcherTest:

    public function testTrailingSlashWorks()
    {
        $coll = new RouteCollection();
        $coll->add('b', new Route('/en-en/{tail}', ['tail' => ''], ['tail' => '.*']));

        $matcher = $this->getUrlMatcher($coll);
        // this works in 4.2.6 and 4.2.7
        $this->assertEquals(['_route' => 'b', 'tail' => ''], $matcher->match('/en-en'));
        $this->assertEquals(['_route' => 'b', 'tail' => 'products'], $matcher->match('/en-en/products'));
        // works in 4.2.6, but does not work in 4.2.7
        $this->assertEquals(['_route' => 'b', 'tail' => ''], $matcher->match('/en-en/'));
    }

So you see the first two assertions work. Just tested this with the Git Repo and switching between the tags.

Don't know how to fix though tbh. @nicolas-grekas should I submit a PR with this additional test?