/c/document_library/get_file URLs not working when language is changed

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X, 7.1.X, 7.2.X, 7.3.X, Master
• Fix Version/s: 7.0.10.13 DXP SP13, 7.0.X, 7.1.10 DXP FP17, 7.1.10.4 SP4, 7.1.X, 7.2.10 DXP FP5, 7.2.10.2 DXP SP2, 7.2.X, 7.3.0 CE GA1, 7.3.1 CE GA2, 7.3.10 DXP GA1, Master
• Component/s: Documents & Media
• Labels:
  • ee-ts
  • liferay-dxp-70-sp13
  • liferay-dxp-71-sp4
  • liferay-dxp-72-sp2
  • liferay-fixpack-de-90-7010
  • liferay-fixpack-dxp-17-7110
  • liferay-fixpack-dxp-5-7210
• Branch Version/s:
  7.2.x, 7.1.x, 7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/83429

Steps to reproduce:

1. Add a basic document (e.g an image file) to site/Content/Documents and Media.
2. Get its uuid, either from the database or from the UI (e.g take it out from Latest Version URL on the document detail view)
3. Deply the attached module. It contains a simple sample portlet that is configured to show a link to the document in the form of /c/document_library/get_file?uuid=<uuid>, and when you click on that link, the file is displayed in your browser (just like when using such a URL from the browser's address bar).
4.Create a page with name "Sample portlet" and place the sample portlet on it.
5. Go to localhost:8080/sample-portlet and open the portlet's configuration.
6. Add the following value in the "Document Link" field:

<a href="/c/document_library/get_file?uuid=<uuid>">Link</a>

where you obviously put in your uuid.
7. Save and then click on the link displayed by the portlet.
Checkpoint: Your file is displayed in the browser.
8. Go back, change the URL to German locale: localhost:8080/de/sample-portlet and click on the link again
Result: The file is not shown, only some gibberish characters. (see screenshots in attached document)