bug #24532 [DI] Fix possible incorrect php-code when dumped strings contains newlines (Strate)

This PR was squashed before being merged into the 2.7 branch (closes #24532).

Discussion
----------

[DI] Fix possible incorrect php-code when dumped strings contains newlines

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | yes
| New feature?  | no <!-- don't forget to update src/**/CHANGELOG.md files -->
| BC breaks?    | no
| Deprecations? | no <!-- don't forget to update UPGRADE-*.md files -->
| Tests pass?   | yes
| Fixed tickets | ?
| License       | MIT
| Doc PR        | no

See discussion #24517

<!--
- Bug fixes must be submitted against the lowest branch where they apply
  (lowest branches are regularly merged to upper ones so they get the fixes too).
- Features and deprecations must be submitted against the 3.4,
  legacy code removals go to the master branch.
- Please fill in this template according to the PR you're about to submit.
- Replace this comment by a description of what your PR is solving.
-->

Commits
-------

345f2fc [DI] Fix possible incorrect php-code when dumped strings contains newlines

Author: nicolas-grekas

src/Symfony/Component/DependencyInjection/Dumper/PhpDumper.php

@@ -1574,6 +1574,13 @@ private function export($value)
             return $dirname;
         }
 
+        if (is_string($value) && false !== strpos($value, "\n")) {
+            $cleanParts = explode("\n", $value);
+            $cleanParts = array_map(function ($part) { return var_export($part, true); }, $cleanParts);
+
+            return implode('."\n".', $cleanParts);
+        }
+
         return var_export($value, true);
     }
 }

src/Symfony/Component/DependencyInjection/Tests/Dumper/PhpDumperTest.php

@@ -55,6 +55,7 @@ public function testDumpOptimizationString()
             'optimize concatenation with empty string' => 'string1%empty_value%string2',
             'optimize concatenation from the start' => '%empty_value%start',
             'optimize concatenation at the end' => 'end%empty_value%',
+            'new line' => "string with \nnew line",
         ));
 
         $container = new ContainerBuilder();

src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services10.php

@@ -56,7 +56,7 @@ public function isFrozen()
      */
     protected function getTestService()
     {
-        return $this->services['test'] = new \stdClass(array('only dot' => '.', 'concatenation as value' => '.\'\'.', 'concatenation from the start value' => '\'\'.', '.' => 'dot as a key', '.\'\'.' => 'concatenation as a key', '\'\'.' => 'concatenation from the start key', 'optimize concatenation' => 'string1-string2', 'optimize concatenation with empty string' => 'string1string2', 'optimize concatenation from the start' => 'start', 'optimize concatenation at the end' => 'end'));
+        return $this->services['test'] = new \stdClass(array('only dot' => '.', 'concatenation as value' => '.\'\'.', 'concatenation from the start value' => '\'\'.', '.' => 'dot as a key', '.\'\'.' => 'concatenation as a key', '\'\'.' => 'concatenation from the start key', 'optimize concatenation' => 'string1-string2', 'optimize concatenation with empty string' => 'string1string2', 'optimize concatenation from the start' => 'start', 'optimize concatenation at the end' => 'end', 'new line' => 'string with '."\n".'new line'));
     }
 
     /**