bug #19435 [Cache] Fix incorrect timestamps generated by FilesystemAd…

…apter (nicolas-grekas)

This PR was merged into the 3.1 branch.

Discussion
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[Cache] Fix incorrect timestamps generated by FilesystemAdapter

| Q             | A
| ------------- | ---
| Branch?       | 3.1
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #19431
| License       | MIT
| Doc PR        | -

Commits
-------

bd2e795 [Cache] Fix incorrect timestamps generated by FilesystemAdapter

src/Symfony/Component/Cache/Adapter/FilesystemAdapter.php

@@ -126,7 +126,7 @@ protected function doDelete(array $ids)
     protected function doSave(array $values, $lifetime)
     {
         $ok = true;
-        $expiresAt = $lifetime ? time() + $lifetime : PHP_INT_MAX;
+        $expiresAt = time() + ($lifetime ?: 31557600); // 31557600s = 1 year
         $tmp = $this->directory.uniqid('', true);
 
         foreach ($values as $id => $value) {