bug symfony#28636 [HttpFoundation] X-Accel-Mapping does not use HTTP key=value syntax (c960657)

This PR was squashed before being merged into the 4.1 branch (closes symfony#28636).

Discussion
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[HttpFoundation] X-Accel-Mapping does not use HTTP key=value syntax

| Q             | A
| ------------- | ---
| Branch?       | 4.1
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? |no
| Tests pass?   | yes
| Fixed tickets | symfony#28627
| License       | MIT
| Doc PR        |

The `X-Accel-Mapping` header does not use the standard HTTP key=value syntax, so using `HeaderUtils::combine()` breaks paths with upper-case letters.

There is no good reason to use `HeaderUtils::combine()` in this case, so simply skip it.

Commits
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09343c2 [HttpFoundation] X-Accel-Mapping does not use HTTP key=value syntax

Author: fabpot

src/Symfony/Component/HttpFoundation/BinaryFileResponse.php

@@ -219,8 +219,8 @@ public function prepare(Request $request)
                 // Do X-Accel-Mapping substitutions.
                 // @link http://wiki.nginx.org/X-accel#X-Accel-Redirect
                 $parts = HeaderUtils::split($request->headers->get('X-Accel-Mapping', ''), ',=');
-                $mappings = HeaderUtils::combine($parts);
-                foreach ($mappings as $pathPrefix => $location) {
+                foreach ($parts as $part) {
+                    list($pathPrefix, $location) = $part;
                     if (substr($path, 0, \strlen($pathPrefix)) === $pathPrefix) {
                         $path = $location.substr($path, \strlen($pathPrefix));
                         break;

src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php

@@ -337,7 +337,8 @@ public function getSampleXAccelMappings()
     {
         return array(
             array('/var/www/var/www/files/foo.txt', '/var/www/=/files/', '/files/var/www/files/foo.txt'),
-            array('/home/foo/bar.txt', '/var/www/=/files/,/home/foo/=/baz/', '/baz/bar.txt'),
+            array('/home/Foo/bar.txt', '/var/www/=/files/,/home/Foo/=/baz/', '/baz/bar.txt'),
+            array('/home/Foo/bar.txt', '"/var/www/"="/files/", "/home/Foo/"="/baz/"', '/baz/bar.txt'),
         );
     }