M core/file_api.php

• Changed file_get_display_name() to handle doc-001-xyz.zip format.

M proj_doc_edit_page.php

• Use file_get_display_name() to display the original filename rather
  than the file system file name.

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2021 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9