Character in hyperlink changed after save, from % to %25

Summary

Adding new link in the editor or in comments with special character %, after save link will be modified and character % will be replaced with %25.

The Issue is not present in 5.9.14. 

Environment

• Centos 7
• Java 1.8.0_111
• Embedded Database

Steps to Reproduce

1. Edit page
2. Create the link with % in URL. eg. http://testing.com/1%
3. Save page
4. Target of link will change to http://testing.com/1%25

Expected Results

• Link target should remain same as in editor, eg. http://testing.com/1%

Actual Results

• The link will be modified and character % will be replaced with %25.

Notes

Tested in Confluence 5.9.14. The functionality works as expected.

Workaround

1. Install the Confluence Source Editor (free add-on)
2. Edit the page
3. Click on the <> icon in the top right
4. Find the href= attribute that contains the '%25' in the URL
5. Replace it with just '%'
6. Apply the changes and save the page