Confluence is sharing, via email, wrong link to the preview of attachments in pages with special titles (result: Page Not Found)

A wrong URL is received via email when it is shared the link of a preview of attachment at page with special characters in the title.

Steps to reproduce:

• Create a page with special characters in the title (e.g. "(", ")" or "@");
• Upload and include an attachment;
• Save the page;
• Click to preview the attachment;
• Share the attachment (not the page) with your user or email;
• Go to your mail inbox, open the email received from confluence, click to open the link to the attachment (not the link to the page).
• Result: Page Not Found

Causes:

The link to preview attachments, in pages with titles with special characters, is something like that:
<base url>/pages/viewpage.action?pageId=<num>&preview=<attachment>...

e.g: http://localhost:8090/pages/viewpage.action?pageId=720902&preview=/720902/720904/A-Page-060415-1713-41.pdf

However, when Confluence shares the link to the preview of the attachment, instead of inserting a "&" after the pageId=<num>, Confluence is inserting a wrong additional "?", such as:

<base url>/pages/viewpage.action?pageId=<num>?preview=<attachment>...

e.g: http://localhost:8090/pages/viewpage.action?pageId=720902?preview=/720902/720904/A-Page-060415-1713-41.pdf

Workaround:

Change the page title, removing the special characters.