fix error on CSS includes on windows

The regex wasn't properly escaped here which lead to problems when the
path contains backslashes. This is the root cause of the bug reported
at https://github.com/cosmocode/edittable/issues/19

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/exe/css.php b/lib/exe/css.php
index c96dedd37..f273b7ee4 100644
--- a/lib/exe/css.php
+++ b/lib/exe/css.php
@@ -456,8 +456,9 @@ class DokuCssFile {
             if (defined('DOKU_UNITTEST')) {
                 $basedir[] = realpath(TMP_DIR);
             }
-            $regex = '#^('.join('|',$basedir).')#';
 
+            $basedir = array_map('preg_quote_cb', $basedir);
+            $regex = '/^('.join('|',$basedir).')/';
             $this->relative_path = preg_replace($regex, '', dirname($this->filepath));
         }