There is no error message when drag and drop files from computer

• Type: Bug
• Status: Verified
• Resolution: Unresolved
• Affects Version/s: 7.0.3 CE GA4, 7.0.X, Master
• Fix Version/s: None
• Component/s: DM > Administration
• Labels:
  • 7.2-won't
  • QA-V
  • SMEQAFP3
  • frontend
• Fix Priority: 3
• Sprint: 010 - Caterpie

Steps to reproduce:

1. Use any browser with HTML5 file upload capability (Chrome for example).
2. In computer OS (tested with Ubuntu), open a folder navigation window where it contains a file (the small weight the better).
3. Go to Control Panel --> Liferay --> Documents & Media.
4. Drag file and drop into Documents & Media initial page.
5. You will see the "Completed" message showing in the middle of the file.
6. Drag & drop the file again.

 Expected behavior: You should see an error message like "Please enter a unique name" somewhere

 Actual behavior: No error message shows. This can make users think upload was succesful. But after refreshing page, file isn't there anymore.