Anchor links are lost if page title contains certain special characters

Steps to Reproduce

1. Create a page with title åê
2. Insert the following Wiki Markup to the page:

   {toc}
   
   h1. Heading 1
   {loremipsum}
   {loremipsum}
   
   h1. Heading 2
   {loremipsum}
   
   h1. Heading 3
   {loremipsum}
   

3. Save the page
4. Copy the link of "Heading 2" from the Table of Contents macro, which should be in the following format:

   http://<confluence-url>/pages/viewpage.action?pageId=<contentID>#id-åê-Heading2

   

5. Create a new page titled "Test"
6. Paste the copied link into the editor and then save the page
7. Click on the link

Expected Results

When the page åê loads, it should point to the correct anchor heading (i.e. "Heading 2").

Actual Results

The page does NOT point to the correct anchor heading (it shows the content as if the anchor is not defined/incorrect)

Environment Information

Tested on Confluence 4.3.5, 4.3.7, 5.0.1 using Chrome

Findings

When the link is pasted into the editor, the XHTML code is:

  <ac:link ac:anchor="åê-Heading2">
    <ri:page ri:content-title="åê"/>
  </ac:link>

This is wrong. The anchor name should be without åê-:

  <ac:link ac:anchor="Heading2">
    <ri:page ri:content-title="åê"/>
  </ac:link>

NOTE: This issue does not occur when the source page does not include special characters.

Workaround

1. Instead of pasting the link directly into the editor, click the "Link" icon instead and under "Web Link", paste the link into the text box
2. Edit the link and change it from

   åê#åê-Heading2

   to

   åê#Heading2

   This means that the characters between # and - need to be deleted (including the - character).

3. Edit the anchor name using the Source Code Editor