bug #10937 [HttpKernel] Fix "absolute path" when we look to the cache directory (BenoitLeveque)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #10937).

Discussion
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[HttpKernel] Fix "absolute path" when we look to the cache directory

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

We should get ``__DIR__`` instead of ``__DIR__ . '/.'``

I've seen this issue when trying to play with the symfony standard new directory structure

Commits
-------

4735e56 Fix "absolute path" when we look to the cache directory

src/Symfony/Component/HttpKernel/Kernel.php

@@ -748,9 +748,15 @@ abstract class Kernel implements KernelInterface, TerminableInterface
         $filesystem = new Filesystem();
 
         return preg_replace_callback("{'([^']*)(".preg_quote($rootDir)."[^']*)'}", function ($match) use ($filesystem, $cacheDir) {
-            $prefix = isset($match[1]) && $match[1] ? "'$match[1]'.__DIR__.'/" : "__DIR__.'/";
+            $prefix = isset($match[1]) && $match[1] ? "'$match[1]'.__DIR__" : "__DIR__";
 
-            return $prefix.rtrim($filesystem->makePathRelative($match[2], $cacheDir), '/')."'";
+            $relativePath = rtrim($filesystem->makePathRelative($match[2], $cacheDir), '/');
+
+            if ($relativePath === '.') {
+                return $prefix;
+            }
+
+            return $prefix . ".'/" . $relativePath . "'";
         }, $content);
     }
 

src/Symfony/Component/HttpKernel/Tests/Fixtures/DumpedContainers/app/cache/dev/withAbsolutePaths.php

@@ -1,6 +1,7 @@
 'ROOT_DIR/app/cache/dev/foo'
 'ROOT_DIR/app/cache/foo'
 'ROOT_DIR/foo/bar.php'
+'ROOT_DIR/app/cache/dev'
 
 '/some/where/else/foo'
 

src/Symfony/Component/HttpKernel/Tests/Fixtures/DumpedContainers/app/cache/dev/withoutAbsolutePaths.php

@@ -1,6 +1,7 @@
 __DIR__.'/foo'
 __DIR__.'/../foo'
 __DIR__.'/../../../foo/bar.php'
+__DIR__
 
 '/some/where/else/foo'