From 2bc11505f4c2a932101748bfbc582993c91274fd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Auswo=CC=88ger?= <martin@auswoeger.com>
Date: Thu, 6 Apr 2017 20:04:32 +0200
Subject: [PATCH] [Filesystem] Fixed makePathRelative

---
 .../Component/Filesystem/Filesystem.php       | 42 +++++++++----------
 .../Filesystem/Tests/FilesystemTest.php       | 12 ++++++
 2 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index edfc1b9d46..ac2a1c7857 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -358,25 +358,28 @@ class Filesystem
             $startPath = str_replace('\\', '/', $startPath);
         }
 
+        $stripDriveLetter = function ($path) {
+            if (strlen($path) > 2 && ':' === $path[1] && '/' === $path[2] && ctype_alpha($path[0])) {
+                return substr($path, 2);
+            }
+
+            return $path;
+        };
+
+        $endPath = $stripDriveLetter($endPath);
+        $startPath = $stripDriveLetter($startPath);
+
         // Split the paths into arrays
         $startPathArr = explode('/', trim($startPath, '/'));
         $endPathArr = explode('/', trim($endPath, '/'));
 
-        if ('/' !== $startPath[0]) {
-            array_shift($startPathArr);
-        }
-
-        if ('/' !== $endPath[0]) {
-            array_shift($endPathArr);
-        }
-
-        $normalizePathArray = function ($pathSegments) {
+        $normalizePathArray = function ($pathSegments, $absolute) {
             $result = array();
 
             foreach ($pathSegments as $segment) {
-                if ('..' === $segment) {
+                if ('..' === $segment && ($absolute || count($result))) {
                     array_pop($result);
-                } else {
+                } elseif ('.' !== $segment) {
                     $result[] = $segment;
                 }
             }
@@ -384,8 +387,8 @@ class Filesystem
             return $result;
         };
 
-        $startPathArr = $normalizePathArray($startPathArr);
-        $endPathArr = $normalizePathArray($endPathArr);
+        $startPathArr = $normalizePathArray($startPathArr, static::isAbsolutePath($startPath));
+        $endPathArr = $normalizePathArray($endPathArr, static::isAbsolutePath($endPath));
 
         // Find for which directory the common path stops
         $index = 0;
@@ -394,19 +397,14 @@ class Filesystem
         }
 
         // Determine how deep the start path is relative to the common path (ie, "web/bundles" = 2 levels)
-        if (count($startPathArr) === 1 && $startPathArr[0] === '') {
+        if (1 === count($startPathArr) && '' === $startPathArr[0]) {
             $depth = 0;
         } else {
             $depth = count($startPathArr) - $index;
         }
 
-        // When we need to traverse from the start, and we are starting from a root path, don't add '../'
-        if ('/' === $startPath[0] && 0 === $index && 0 === $depth) {
-            $traverser = '';
-        } else {
-            // Repeated "../" for each level need to reach the common path
-            $traverser = str_repeat('../', $depth);
-        }
+        // Repeated "../" for each level need to reach the common path
+        $traverser = str_repeat('../', $depth);
 
         $endPathRemainder = implode('/', array_slice($endPathArr, $index));
 
@@ -500,7 +498,7 @@ class Filesystem
     {
         return strspn($file, '/\\', 0, 1)
             || (strlen($file) > 3 && ctype_alpha($file[0])
-                && substr($file, 1, 1) === ':'
+                && ':' === substr($file, 1, 1)
                 && strspn($file, '/\\', 2, 1)
             )
             || null !== parse_url($file, PHP_URL_SCHEME)
diff --git a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
index ab2395cd00..d2058d0a01 100644
--- a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
+++ b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
@@ -847,6 +847,7 @@ class FilesystemTest extends FilesystemTestCase
             array('/var/lib/symfony/src/Symfony', '/var/lib/symfony/src/Symfony/Component/', '../'),
             array('var/lib/symfony/', 'var/lib/symfony/src/Symfony/Component', '../../../'),
             array('/usr/lib/symfony/', '/var/lib/symfony/src/Symfony/Component', '../../../../../../usr/lib/symfony/'),
+            array('usr/lib/symfony/', 'var/lib/symfony/src/Symfony/Component', '../../../../../../usr/lib/symfony/'),
             array('/var/lib/symfony/src/Symfony/', '/var/lib/symfony/', 'src/Symfony/'),
             array('/aa/bb', '/aa/bb', './'),
             array('/aa/bb', '/aa/bb/', './'),
@@ -878,6 +879,17 @@ class FilesystemTest extends FilesystemTestCase
             array('C:/aa/bb/../../cc', 'C:/aa/../dd/..', 'cc/'),
             array('C:/../aa/bb/cc', 'C:/aa/dd/..', 'bb/cc/'),
             array('C:/../../aa/../bb/cc', 'C:/aa/dd/..', '../bb/cc/'),
+            array('aa/bb', 'aa/cc', '../bb/'),
+            array('aa/cc', 'bb/cc', '../../aa/cc/'),
+            array('aa/bb', 'aa/./cc', '../bb/'),
+            array('aa/./bb', 'aa/cc', '../bb/'),
+            array('aa/./bb', 'aa/./cc', '../bb/'),
+            array('../../', '../../', './'),
+            array('../aa/bb/', 'aa/bb/', '../../../aa/bb/'),
+            array('../../../', '../../', '../'),
+            array('', '', './'),
+            array('', 'aa/', '../'),
+            array('aa/', '', 'aa/'),
         );
 
         if ('\\' === DIRECTORY_SEPARATOR) {