minor symfony#24317 Use PHP_MAXPATHLEN in Filesystem.php (edoger)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes symfony#24317).

Discussion
----------

Use PHP_MAXPATHLEN in Filesystem.php

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

Relative to the use of fixed values, I think the use of PHP_MAXPATHLEN will be more robust.

Commits
-------

7a47559 Use PHP_MAXPATHLEN in Filesystem.

Author: nicolas-grekas

src/Symfony/Component/Filesystem/Filesystem.php

@@ -117,9 +117,11 @@ public function mkdir($dirs, $mode = 0777)
      */
     public function exists($files)
     {
+        $maxPathLength = PHP_MAXPATHLEN - 2;
+
         foreach ($this->toIterator($files) as $file) {
-            if ('\\' === DIRECTORY_SEPARATOR && strlen($file) > 258) {
-                throw new IOException('Could not check if file exist because path length exceeds 258 characters.', 0, null, $file);
+            if (strlen($file) > $maxPathLength) {
+                throw new IOException(sprintf('Could not check if file exist because path length exceeds %d characters.', $maxPathLength), 0, null, $file);
             }
 
             if (!file_exists($file)) {
@@ -301,8 +303,10 @@ public function rename($origin, $target, $overwrite = false)
      */
     private function isReadable($filename)
     {
-        if ('\\' === DIRECTORY_SEPARATOR && strlen($filename) > 258) {
-            throw new IOException('Could not check if file is readable because path length exceeds 258 characters.', 0, null, $filename);
+        $maxPathLength = PHP_MAXPATHLEN - 2;
+
+        if (strlen($filename) > $maxPathLength) {
+            throw new IOException(sprintf('Could not check if file is readable because path length exceeds %d characters.', $maxPathLength), 0, null, $filename);
         }
 
         return is_readable($filename);

src/Symfony/Component/Filesystem/Tests/FilesystemTest.php

@@ -374,16 +374,13 @@ public function testFilesExists()
      */
     public function testFilesExistsFails()
     {
-        if ('\\' !== DIRECTORY_SEPARATOR) {
-            $this->markTestSkipped('Test covers edge case on Windows only.');
-        }
-
         $basePath = $this->workspace.'\\directory\\';
+        $maxPathLength = PHP_MAXPATHLEN - 2;
 
         $oldPath = getcwd();
         mkdir($basePath);
         chdir($basePath);
-        $file = str_repeat('T', 259 - strlen($basePath));
+        $file = str_repeat('T', $maxPathLength - strlen($basePath) + 1);
         $path = $basePath.$file;
         exec('TYPE NUL >>'.$file); // equivalent of touch, we can not use the php touch() here because it suffers from the same limitation
         $this->longPathNamesWindows[] = $path; // save this so we can clean up later