Run the phpunit-bridge from a PR

.travis.yml

@@ -194,6 +194,18 @@ before_install:
       fi
 
 install:
+    - |
+      # Install the phpunit-bridge from a PR if required
+      #
+      # To run a PR with a patched phpunit-bridge, first submit the path for the
+      # phpunit-bridge as a separate PR against the next feature branch then
+      # uncomment and update the following line with the PR number and change the
+      # required version of the bridge in the root composer.json to the version
+      # of the next feature version (e.g "symfony/phpunit-bridge": "4.4.x@dev")
+      git fetch origin refs/pull/32886/head
+      git rm -rq src/Symfony/Bridge/PhpUnit
+      git checkout -q FETCH_HEAD -- src/Symfony/Bridge/PhpUnit
+
     - |
       # Create local composer packages for each patched components and reference them in composer.json files when cross-testing components
       if [[ ! $deps ]]; then
@@ -206,6 +218,8 @@ install:
           mv composer.json composer.json.phpunit &&
           mv composer.json.orig composer.json
       fi
+      git rm -fq -- src/Symfony/Bridge/PhpUnit/composer.json
+      git diff --staged -- src/Symfony/Bridge/PhpUnit/ | git apply -R --index
 
     - |
       # For the master branch, when deps=high, the version before master is checked out and tested with the locally patched components

composer.json

@@ -98,7 +98,7 @@
         "ocramius/proxy-manager": "~0.4|~1.0|~2.0",
         "predis/predis": "~1.0",
         "egulias/email-validator": "~1.2,>=1.2.8|~2.0",
-        "symfony/phpunit-bridge": "^3.4.19|^4.1.8|~5.0",
+        "symfony/phpunit-bridge": "4.4.x@dev",
         "symfony/security-acl": "~2.8|~3.0",
         "phpdocumentor/reflection-docblock": "^3.0|^4.0"
     },

src/Symfony/Component/Debug/Tests/Exception/FlattenExceptionTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Debug\Tests\Exception;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Bridge\PhpUnit\ForwardCompatTestTrait;
 use Symfony\Component\Debug\Exception\FlattenException;
 use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
@@ -31,6 +32,8 @@
 
 class FlattenExceptionTest extends TestCase
 {
+    use ForwardCompatTestTrait;
+
     public function testStatusCode()
     {
         $flattened = FlattenException::create(new \RuntimeException(), 403);
@@ -256,7 +259,7 @@ function () {},
 
         // assertEquals() does not like NAN values.
         $this->assertEquals($array[$i][0], 'float');
-        $this->assertTrue(is_nan($array[$i++][1]));
+        $this->assertNan($array[$i++][1]);
     }
 
     public function testRecursionInArguments()