Label duplicates with - sign with every click of Next or Previous page on "Labelled Content" page due to Label-related Macros

Summary

On a Labelled Content page, browsing for next page will result in duplicated labels.

Steps to reproduce:

1. Have a space that has contain many pages with the same label
2. Go to Popular Label page by either:
   • Browse > Labels on Documentation theme
   • Access using "Popular Labels" macro
   • Access the Labelled Content page directly using the URL: http://<Confluence Base URL>/labels/listlabels-alphaview.action?key=<SPACEKEY>
3. Choose the label that labels many pages in this space
4. the "Labeled Content" page show up with a list of pages that has the same label. Below is an example of the label "decisions"
   
5. Note that the URL is currently:

   http://http://<Confluence Base URL>//label/<SPACEKEY>/<Label chosen>
   

6. Click Next >> to view the next page

Expected Results

Everything that's displayed in the page is still the same except that the next page is shown.

Actual Results

The label now is duplicated and both of them has become "-decisions" "-decisions"

Further observations

For an example of Confluence that has a base URL of http://localhost:15910/confluence, label named "decisions" with label ID of 1015809

Note that the URL changes to the following after clicking "next" from the first page:

http://localhost:15910/confluence/label/5910/decisions?ids=1015809&startIndex=10

If we press the Next button even further, URL changes into the following:

http://localhost:15910/confluence/label/5910/decisions?ids=1015809&ids=1015809&startIndex=20

Note that the "ids=1015809" is duplicated

Notes

1. Using the macro "Labels List" will also give the same behavior
2. View attached screencast for more information