bug #16987 [FileSystem] Windows fix (flip111)

This PR was merged into the 2.3 branch.

Discussion
----------

[FileSystem] Windows fix

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | https://github.com/symfony/symfony/issues/16783
| License       | MIT
| Doc PR        |

* Fixes edge case on windows where PHP does not generate a PHP Warning but instead returns a wrong result https://bugs.php.net/bug.php?id=71103
* Improved error reporting on `unlink` used in `remove()`

Commits
-------

0d5f7e2 Update FileSystem

src/Symfony/Component/Filesystem/Filesystem.php

@@ -100,6 +100,10 @@ class Filesystem
     public function exists($files)
     {
         foreach ($this->toIterator($files) as $file) {
+            if ('\\' === DIRECTORY_SEPARATOR AND strlen($file) > 258) {
+                throw new IOException(sprintf('Could not check if file exist because path length exceeds 258 characters for file "%s"', $file));
+            }
+
             if (!file_exists($file)) {
                 return false;
             }
@@ -139,7 +143,7 @@ class Filesystem
         $files = iterator_to_array($this->toIterator($files));
         $files = array_reverse($files);
         foreach ($files as $file) {
-            if (!file_exists($file) && !is_link($file)) {
+            if (!$this->exists($file) && !is_link($file)) {
                 continue;
             }
 
@@ -157,7 +161,8 @@ class Filesystem
                     }
                 } else {
                     if (true !== @unlink($file)) {
-                        throw new IOException(sprintf('Failed to remove file %s', $file));
+                        $error = error_get_last();
+                        throw new IOException(sprintf('Failed to remove file "%s": %s.', $file, $error['message']));
                     }
                 }
             }
@@ -253,7 +258,7 @@ class Filesystem
     public function rename($origin, $target, $overwrite = false)
     {
         // we check that target does not exist
-        if (!$overwrite && is_readable($target)) {
+        if (!$overwrite && $this->isReadable($target)) {
             throw new IOException(sprintf('Cannot rename because the target "%s" already exist.', $target));
         }
 
@@ -262,6 +267,22 @@ class Filesystem
         }
     }
 
+    /**
+     * Tells whether a file exists and is readable.
+     *
+     * @param string $filename Path to the file.
+     *
+     * @throws IOException When windows path is longer than 258 characters
+     */
+    private function isReadable($filename)
+    {
+        if ('\\' === DIRECTORY_SEPARATOR AND strlen($filename) > 258) {
+            throw new IOException(sprintf('Could not check if file is readable because path length exceeds 258 characters for file "%s"', $filename));
+        }
+
+        return is_readable($filename);
+    }
+
     /**
      * Creates a symbolic link or copy a directory.
      *

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

@@ -19,6 +19,7 @@ use Symfony\Component\Filesystem\Filesystem;
 class FilesystemTest extends \PHPUnit_Framework_TestCase
 {
     private $umask;
+    private $longPathNamesWindows = array();
 
     /**
      * @var string
@@ -56,6 +57,12 @@ class FilesystemTest extends \PHPUnit_Framework_TestCase
 
     protected function tearDown()
     {
+        if (!empty($this->longPathNamesWindows)) {
+            foreach ($this->longPathNamesWindows as $path) {
+                exec('DEL '.$path);
+            }
+        }
+
         $this->filesystem->remove($this->workspace);
         umask($this->umask);
     }
@@ -354,6 +361,28 @@ class FilesystemTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue($this->filesystem->exists($basePath.'folder'));
     }
 
+    /**
+     * @expectedException \Symfony\Component\Filesystem\Exception\IOException
+     */
+    public function testFilesExistsFails()
+    {
+        if ('\\' !== DIRECTORY_SEPARATOR) {
+            $this->markTestSkipped('Test covers edge case on Windows only.');
+        }
+
+        $basePath = $this->workspace.'\\directory\\';
+
+        $oldPath = getcwd();
+        mkdir($basePath);
+        chdir($basePath);
+        $file = str_repeat('T', 259 - strlen($basePath));
+        $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[] = $path; // save this so we can clean up later
+        chdir($oldPath);
+        $this->filesystem->exists($path);
+    }
+
     public function testFilesExistsTraversableObjectOfFilesAndDirectories()
     {
         $basePath = $this->workspace.DIRECTORY_SEPARATOR;