Sharepoint 2016 - Document file extension can be changed or removed

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.1.X, Master
• Fix Version/s: 7.1.X, 7.2.X, Master
• Component/s: Collaboration, Documents & Media, External Document Repositories > Sharepoint
• Labels: None
• Branch Version/s:
  7.2.x, 7.1.x
• Backported to Branch:
  Committed
• Fix Priority: 4
• Sprint: 006 - Charizard
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal-ee/pull/20957

Steps to reproduce:

1. Add Sharepoint 2016 repository
2. Add new document with file extension (e.g. Document_1.png)
3. Change file extension by renaming the document (e.g. Document_1.doc)
4. Save

Expected result:
User cannot edit the file extension. The document file extension is not changed. Two error messages appear:
Your request failed to complete
The source file does not have the same extension as the original file

Actual result:
Document extension is successfully changed. Same behavior when file extension is removed.

Reproduced on:
Tomcat 9.0.6 + MySQL 5.6
Portal 7.1.x-private GIT ID: 05def77a5a615ae9e700986166d8585e7266ff8f
Portal 7.1.x GIT ID: 028a6aa46e0c237d8c93d07b8d8986b06b4799ad