[FrameworkBundle] fix cache:clear command

[nicolas-grekas]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	#12893
License	MIT
Doc PR	-

Reading comment on #12893 stating that using absolute paths works around the pb, I tried using realpath(),
and it works!
Pending work on #12955 can be done quietly now.

[jderusse]

If $realCacheDir does not exists, realpath file returns false

[nicolas-grekas]

The path exists because we checked it a few lines above with is_writable()

[1ed]

@nicolas-grekas great catch.

It works great, but this way cache:warmup and cache:clear not produces the same result, but I think it doesn't really matter.

Here are my results:

    public function getCacheDir()
    {
        return '/tmp/sf/'.$this->getEnvironment();
    }

The partial diff of cache:warmup vs cache:clear

             'kernel.root_dir' => '/home/egabor/dev/OSS/symfony-standard/app',
             'kernel.environment' => 'dev',
             'kernel.debug' => true,
-            'kernel.name' => 'app',
+            'kernel.name' => 'ap_',
             'kernel.cache_dir' => __DIR__,
             'kernel.logs_dir' => '/home/egabor/dev/OSS/symfony-standard/app/logs',
             'kernel.bundles' => array(

    public function getCacheDir()
    {
        return __DIR__.'/../../../../../../../tmp/sf/'.$this->getEnvironment();
    }

The partial diff of cache:warmup vs cache:clear

             'kernel.root_dir' => '/home/egabor/dev/OSS/symfony-standard/app',
             'kernel.environment' => 'dev',
             'kernel.debug' => true,
-            'kernel.name' => 'app',
-            'kernel.cache_dir' => ('/home/egabor/dev/OSS/symfony-standard/app/../../../../../../..'.__DIR__),
+            'kernel.name' => 'ap_',
+            'kernel.cache_dir' => __DIR__,
             'kernel.logs_dir' => '/home/egabor/dev/OSS/symfony-standard/app/logs',
             'kernel.bundles' => array(

[nicolas-grekas]

I added a realpath() in the Kernel that removes the diff for kernel.cache_dir.
The diff for kernel.name is not new, and thus not related to the issue we're working on.
Kernel::getKernelParameters() is always called after the dirs are created thus this realpath should never fail

[fabpot]

Thank you @nicolas-grekas.