Fix HTML escaping of to-source links

This PR was merged into the 2.3 branch.

Discussion
----------

CS: Pre incrementation/decrementation should be used if possible

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

Fixes provided by new fixer: https://github.com/FriendsOfPHP/PHP-CS-Fixer/pull/1113

If this pr is merged I would change the level of the fixer to `symfony`.

Commits
-------

c5123d6 CS: Pre incrementation/decrementation should be used if possible

ExceptionHandler.php

@@ -157,10 +157,11 @@ EOF
                         }
                         if (isset($trace['file']) && isset($trace['line'])) {
                             if ($linkFormat = ini_get('xdebug.file_link_format')) {
-                                $link = str_replace(array('%f', '%l'), array($trace['file'], $trace['line']), $linkFormat);
-                                $content .= sprintf(' in <a href="%s" title="Go to source">%s line %s</a>', $link, $trace['file'], $trace['line']);
+                                $link = strtr($linkFormat, array('%f' => $trace['file'], '%l' => $trace['line']));
+                                $link = htmlspecialchars($link, $flags, $this->charset);
+                                $content .= sprintf(' in <a href="%s" title="Go to source">%s line %d</a>', $link, htmlspecialchars($trace['file'], $flags, $this->charset), $trace['line']);
                             } else {
-                                $content .= sprintf(' in %s line %s', $trace['file'], $trace['line']);
+                                $content .= sprintf(' in %s line %d', htmlspecialchars($trace['file'], $flags, $this->charset), $trace['line']);
                             }
                         }
                         $content .= "</li>\n";

Tests/Exception/FlattenExceptionTest.php

@@ -189,9 +189,9 @@ class FlattenExceptionTest extends \PHPUnit_Framework_TestCase
     public function testTooBigArray()
     {
         $a = array();
-        for ($i = 0; $i < 20; $i++) {
-            for ($j = 0; $j < 50; $j++) {
-                for ($k = 0; $k < 10; $k++) {
+        for ($i = 0; $i < 20; ++$i) {
+            for ($j = 0; $j < 50; ++$j) {
+                for ($k = 0; $k < 10; ++$k) {
                     $a[$i][$j][$k] = 'value';
                 }
             }