bug symfony#25022 [Filesystem] Updated Filesystem::makePathRelative (inso)

This PR was merged into the 4.0-dev branch.

Discussion
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[Filesystem] Updated Filesystem::makePathRelative

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

Removed checks for absolute paths since Symfony >= 4.0 drops support for relative paths.

Commits
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9da7c50 removed checks for absolute paths

Author: nicolas-grekas

src/Symfony/Component/Filesystem/Filesystem.php

@@ -480,11 +480,11 @@ public function makePathRelative($endPath, $startPath)
         $startPathArr = explode('/', trim($startPath, '/'));
         $endPathArr = explode('/', trim($endPath, '/'));
 
-        $normalizePathArray = function ($pathSegments, $absolute) {
+        $normalizePathArray = function ($pathSegments) {
             $result = array();
 
             foreach ($pathSegments as $segment) {
-                if ('..' === $segment && ($absolute || count($result))) {
+                if ('..' === $segment) {
                     array_pop($result);
                 } elseif ('.' !== $segment) {
                     $result[] = $segment;
@@ -494,8 +494,8 @@ public function makePathRelative($endPath, $startPath)
             return $result;
         };
 
-        $startPathArr = $normalizePathArray($startPathArr, static::isAbsolutePath($startPath));
-        $endPathArr = $normalizePathArray($endPathArr, static::isAbsolutePath($endPath));
+        $startPathArr = $normalizePathArray($startPathArr);
+        $endPathArr = $normalizePathArray($endPathArr);
 
         // Find for which directory the common path stops
         $index = 0;